document_title: Game theory

question_text: who gave the concept of game theory first

question_tokens: who gave the concept of game theory first

text: Game theory

text: History[edit]

text: Early discussions of examples of two-person games occurred long before the rise of modern, mathematical game theory. The first known discussion of game theory occurred in a letter written by Charles Waldegrave, an active Jacobite, and uncle to James Waldegrave, a British diplomat, in 1713.[2] In this letter, Waldegrave provides a minimax mixed strategy solution to a two-person version of the card game le Her, and the problem is now known as Waldegrave problem. James Madison made what we now recognize as a game-theoretic analysis of the ways states can be expected to behave under different systems of taxation.[3][4] In his 1838 Recherches sur les principes mathématiques de la théorie des richesses (Researches into the Mathematical Principles of the Theory of Wealth), Antoine Augustin Cournot considered a duopoly and presents a solution that is a restricted version of the Nash equilibrium.

text: In 1913, Ernst Zermelo published Über eine Anwendung der Mengenlehre auf die Theorie des Schachspiels (On an Application of Set Theory to the Theory of the Game of Chess). It proved that the optimal chess strategy is strictly determined. This paved the way for more general theorems.[5]:429

text: In 1938, the Danish mathematical economist Frederik Zeuthen proved that the mathematical model had a winning strategy by using Brouwer's fixed point theorem.[6] In his 1938 book Applications aux Jeux de Hasard and earlier notes, Émile Borel proved a minimax theorem for two-person zero-sum matrix games only when the pay-off matrix was symmetric. Borel conjectured that non-existence of mixed-strategy equilibria in two-person zero-sum games would occur, a conjecture that was proved false.

text: Game theory did not really exist as a unique field until John von Neumann published a paper in 1928.[7] Von Neumann's original proof used Brouwer's fixed-point theorem on continuous mappings into compact convex sets, which became a standard method in game theory and mathematical economics. His paper was followed by his 1944 book Theory of Games and Economic Behavior co-authored with Oskar Morgenstern.[8] The second edition of this book provided an axiomatic theory of utility, which reincarnated Daniel Bernoulli's old theory of utility (of the money) as an independent discipline. Von Neumann's work in game theory culminated in this 1944 book. This foundational work contains the method for finding mutually consistent solutions for two-person zero-sum games. During the following time period, work on game theory was primarily focused on cooperative game theory, which analyzes optimal strategies for groups of individuals, presuming that they can enforce agreements between them about proper strategies.[9]

text: In 1950, the first mathematical discussion of the prisoner's dilemma appeared, and an experiment was undertaken by notable mathematicians Merrill M. Flood and Melvin Dresher, as part of the RAND Corporation's investigations into game theory. RAND pursued the studies because of possible applications to global nuclear strategy.[10] Around this same time, John Nash developed a criterion for mutual consistency of players' strategies, known as Nash equilibrium, applicable to a wider variety of games than the criterion proposed by von Neumann and Morgenstern. Nash proved that every n-player, non-zero-sum (not just 2-player zero-sum) non-cooperative game has what is now known as a Nash equilibrium.

text: Game theory experienced a flurry of activity in the 1950s, during which time the concepts of the core, the extensive form game, fictitious play, repeated games, and the Shapley value were developed. In addition, the first applications of game theory to philosophy and political science occurred during this time.

text: Prize-winning achievements[edit]

text: In 1965, Reinhard Selten introduced his solution concept of subgame perfect equilibria, which further refined the Nash equilibrium (later he would introduce trembling hand perfection as well). In 1994 Nash, Selten and Harsanyi became Economics Nobel Laureates for their contributions to economic game theory.

text: In the 1970s, game theory was extensively applied in biology, largely as a result of the work of John Maynard Smith and his evolutionarily stable strategy. In addition, the concepts of correlated equilibrium, trembling hand perfection, and common knowledge[11] were introduced and analyzed.

text: In 2005, game theorists Thomas Schelling and Robert Aumann followed Nash, Selten and Harsanyi as Nobel Laureates. Schelling worked on dynamic models, early examples of evolutionary game theory. Aumann contributed more to the equilibrium school, introducing an equilibrium coarsening, correlated equilibrium, and developing an extensive formal analysis of the assumption of common knowledge and of its consequences.

text: In 2007, Leonid Hurwicz, together with Eric Maskin and Roger Myerson, was awarded the Nobel Prize in Economics "for having laid the foundations of mechanism design theory". Myerson's contributions include the notion of proper equilibrium, and an important graduate text: Game Theory, Analysis of Conflict.[1] Hurwicz introduced and formalized the concept of incentive compatibility.

text: In 2012, Alvin E. Roth and Lloyd S. Shapley were awarded the Nobel Prize in Economics "for the theory of stable allocations and the practice of market design" and, in 2014, the Nobel went to game theorist Jean Tirole.

text: Game types[edit]

text: Cooperative / Non-cooperative[edit]

text: A game is cooperative if the players are able to form binding commitments externally enforced (e.g. through contract law). A game is non-cooperative if players cannot form alliances or if all agreements need to be self-enforcing (e.g. through credible threats).[1]

text: Cooperative games are often analysed through the framework of cooperative game theory, which focuses on predicting which coalitions will form, the joint actions that groups take and the resulting collective payoffs. It is opposed to the traditional non-cooperative game theory which focuses on predicting individual players' actions and payoffs and analyzing Nash equilibria.[2] [3]

text: Cooperative game theory provides a high-level approach as it only describes the structure, strategies and payoffs of coalitions, whereas non-cooperative game theory also looks at how bargaining procedures will affect the distribution of payoffs within each coalition. As non-cooperative game theory is more general, cooperative games can be analyzed through the approach of non-cooperative game theory (the converse does not hold) provided that sufficient assumptions are made to encompass all the possible strategies available to players due to the possibility of external enforcement of cooperation. While it would thus be optimal to have all games expressed under a non-cooperative framework, in many instances insufficient information is available to accurately model the formal procedures available to the players during the strategic bargaining process, or the resulting model would be of too high complexity to offer a practical tool in the real world. In such cases, cooperative game theory provides a simplified approach that allows analysis of the game at large without having to make any assumption about bargaining powers.

text: Symmetric / Asymmetric[edit]

text:
E
F

E
1, 2
0, 0

F
0, 0
1, 2

An asymmetric game

text: A symmetric game is a game where the payoffs for playing a particular strategy depend only on the other strategies employed, not on who is playing them. If the identities of the players can be changed without changing the payoff to the strategies, then a game is symmetric. Many of the commonly studied 2×2 games are symmetric. The standard representations of chicken, the prisoner's dilemma, and the stag hunt are all symmetric games. Some[who?] scholars would consider certain asymmetric games as examples of these games as well. However, the most common payoffs for each of these games are symmetric.

text: Most commonly studied asymmetric games are games where there are not identical strategy sets for both players. For instance, the ultimatum game and similarly the dictator game have different strategies for each player. It is possible, however, for a game to have identical strategies for both players, yet be asymmetric. For example, the game pictured to the right is asymmetric despite having identical strategy sets for both players.

text: Zero-sum / Non-zero-sum[edit]

text:
A
B

A
–1, 1
3, –3

B
0, 0
–2, 2

A zero-sum game

text: Zero-sum games are a special case of constant-sum games, in which choices by players can neither increase nor decrease the available resources. In zero-sum games the total benefit to all players in the game, for every combination of strategies, always adds to zero (more informally, a player benefits only at the equal expense of others).[12] Poker exemplifies a zero-sum game (ignoring the possibility of the house's cut), because one wins exactly the amount one's opponents lose. Other zero-sum games include matching pennies and most classical board games including Go and chess.

text: Many games studied by game theorists (including the famed prisoner's dilemma) are non-zero-sum games, because the outcome has net results greater or less than zero. Informally, in non-zero-sum games, a gain by one player does not necessarily correspond with a loss by another.

text: Constant-sum games correspond to activities like theft and gambling, but not to the fundamental economic situation in which there are potential gains from trade. It is possible to transform any game into a (possibly asymmetric) zero-sum game by adding a dummy player (often called "the board") whose losses compensate the players' net winnings.

text: Simultaneous / Sequential[edit]

text: Simultaneous games are games where both players move simultaneously, or if they do not move simultaneously, the later players are unaware of the earlier players' actions (making them effectively simultaneous). Sequential games (or dynamic games) are games where later players have some knowledge about earlier actions. This need not be perfect information about every action of earlier players; it might be very little knowledge. For instance, a player may know that an earlier player did not perform one particular action, while he does not know which of the other available actions the first player actually performed.

text: The difference between simultaneous and sequential games is captured in the different representations discussed above. Often, normal form is used to represent simultaneous games, while extensive form is used to represent sequential ones. The transformation of extensive to normal form is one way, meaning that multiple extensive form games correspond to the same normal form. Consequently, notions of equilibrium for simultaneous games are insufficient for reasoning about sequential games; see subgame perfection.

text: In short, the differences between sequential and simultaneous games are as follows:

text:
Sequential
Simultaneous

Normally denoted by
Decision trees
Payoff matrices

Prior knowledge
of opponent's move?

Yes
No

Time axis?
Yes
No

Also known as

Extensive-form game
Extensive game

Strategy game
Strategic game

text: Perfect information and imperfect information[edit]

text: An important subset of sequential games consists of games of perfect information. A game is one of perfect information if all players know the moves previously made by all other players. Most games studied in game theory are imperfect-information games.[citation needed] Examples of perfect-information games include tic-tac-toe, checkers, infinite chess, and Go.[13][14][15][16]

text: Many card games are games of imperfect information, such as poker and bridge.[17] Perfect information is often confused with complete information, which is a similar concept.[citation needed] Complete information requires that every player know the strategies and payoffs available to the other players but not necessarily the actions taken. Games of incomplete information can be reduced, however, to games of imperfect information by introducing "moves by nature".[18]

text: Combinatorial games[edit]

text: Games in which the difficulty of finding an optimal strategy stems from the multiplicity of possible moves are called combinatorial games. Examples include chess and go. Games that involve imperfect information may also have a strong combinatorial character, for instance backgammon. There is no unified theory addressing combinatorial elements in games. There are, however, mathematical tools that can solve particular problems and answer general questions.[19]

text: Games of perfect information have been studied in combinatorial game theory, which has developed novel representations, e.g. surreal numbers, as well as combinatorial and algebraic (and sometimes non-constructive) proof methods to solve games of certain types, including "loopy" games that may result in infinitely long sequences of moves. These methods address games with higher combinatorial complexity than those usually considered in traditional (or "economic") game theory.[20][21] A typical game that has been solved this way is hex. A related field of study, drawing from computational complexity theory, is game complexity, which is concerned with estimating the computational difficulty of finding optimal strategies.[22]

text: Research in artificial intelligence has addressed both perfect and imperfect information games that have very complex combinatorial structures (like chess, go, or backgammon) for which no provable optimal strategies have been found. The practical solutions involve computational heuristics, like alpha-beta pruning or use of artificial neural networks trained by reinforcement learning, which make games more tractable in computing practice.[19][23]

text: Infinitely long games[edit]

text: Games, as studied by economists and real-world game players, are generally finished in finitely many moves. Pure mathematicians are not so constrained, and set theorists in particular study games that last for infinitely many moves, with the winner (or other payoff) not known until after all those moves are completed.

text: The focus of attention is usually not so much on the best way to play such a game, but whether one player has a winning strategy. (It can be proven, using the axiom of choice, that there are games – even with perfect information and where the only outcomes are "win" or "lose" – for which neither player has a winning strategy.) The existence of such strategies, for cleverly designed games, has important consequences in descriptive set theory.

text: Discrete and continuous games[edit]

text: Much of game theory is concerned with finite, discrete games, that have a finite number of players, moves, events, outcomes, etc. Many concepts can be extended, however. Continuous games allow players to choose a strategy from a continuous strategy set. For instance, Cournot competition is typically modeled with players' strategies being any non-negative quantities, including fractional quantities.

text: Differential games[edit]

text: Differential games such as the continuous pursuit and evasion game are continuous games where the evolution of the players' state variables is governed by differential equations. The problem of finding an optimal strategy in a differential game is closely related to the optimal control theory. In particular, there are two types of strategies: the open-loop strategies are found using the Pontryagin maximum principle while the closed-loop strategies are found using Bellman's Dynamic Programming method.

text: A particular case of differential games are the games with a random time horizon.[24] In such games, the terminal time is a random variable with a given probability distribution function. Therefore, the players maximize the mathematical expectation of the cost function. It was shown that the modified optimization problem can be reformulated as a discounted differential game over an infinite time interval.

text: Many-player and population games[edit]

text: Games with an arbitrary, but finite, number of players are often called n-person games.[25] Evolutionary game theory considers games involving a population of decision makers, where the frequency with which a particular decision is made can change over time in response to the decisions made by all individuals in the population. In biology, this is intended to model (biological) evolution, where genetically programmed organisms pass along some of their strategy programming to their offspring. In economics, the same theory is intended to capture population changes because people play the game many times within their lifetime, and consciously (and perhaps rationally) switch strategies.[26]

text: Stochastic outcomes (and relation to other fields)[edit]

text: Individual decision problems with stochastic outcomes are sometimes considered "one-player games". These situations are not considered game theoretical by some authors.[by whom?] They may be modeled using similar tools within the related disciplines of decision theory, operations research, and areas of artificial intelligence, particularly AI planning (with uncertainty) and multi-agent system. Although these fields may have different motivators, the mathematics involved are substantially the same, e.g. using Markov decision processes (MDP).[citation needed]

text: Stochastic outcomes can also be modeled in terms of game theory by adding a randomly acting player who makes "chance moves" ("moves by nature").[27] This player is not typically considered a third player in what is otherwise a two-player game, but merely serves to provide a roll of the dice where required by the game.

text: For some problems, different approaches to modeling stochastic outcomes may lead to different solutions. For example, the difference in approach between MDPs and the minimax solution is that the latter considers the worst-case over a set of adversarial moves, rather than reasoning in expectation about these moves given a fixed probability distribution. The minimax approach may be advantageous where stochastic models of uncertainty are not available, but may also be overestimating extremely unlikely (but costly) events, dramatically swaying the strategy in such scenarios if it is assumed that an adversary can force such an event to happen.[28] (See Black swan theory for more discussion on this kind of modeling issue, particularly as it relates to predicting and limiting losses in investment banking.)

text: General models that include all elements of stochastic outcomes, adversaries, and partial or noisy observability (of moves by other players) have also been studied. The "gold standard" is considered to be partially observable stochastic game (POSG), but few realistic problems are computationally feasible in POSG representation.[28]

text: Metagames[edit]

text: These are games the play of which is the development of the rules for another game, the target or subject game. Metagames seek to maximize the utility value of the rule set developed. The theory of metagames is related to mechanism design theory.

text: The term metagame analysis is also used to refer to a practical approach developed by Nigel Howard.[29] whereby a situation is framed as a strategic game in which stakeholders try to realise their objectives by means of the options available to them. Subsequent developments have led to the formulation of confrontation analysis.

text: Pooling games[edit]

text: These are games prevailing over all forms of society. Pooling games are repeated plays with changing payoff table in general over an experienced path and their equilibrium strategies usually take a form of evolutionary social convention and economic convention. Pooling game theory emerges to formally recognize the interaction between optimal choice in one play and the emergence of forthcoming payoff table update path, identify the invariance existence and robustness, and predict variance over time. The theory is based upon topological transformation classification of payoff table update over time to predict variance and invariance, and is also within the jurisdiction of the computational law of reachable optimality for ordered system.[30]

text: Mean field game theory[edit]

text: Mean field game theory is the study of strategic decision making in very large populations of small interacting agents. This class of problems was considered in the economics literature by Boyan Jovanovic and Robert W. Rosenthal, in the engineering literature by Peter E. Caines and by mathematician Pierre-Louis Lions and Jean-Michel Lasry.

text: Representation of games[edit]

text: The games studied in game theory are well-defined mathematical objects. To be fully defined, a game must specify the following elements: the players of the game, the information and actions available to each player at each decision point, and the payoffs for each outcome. (Eric Rasmusen refers to these four "essential elements" by the acronym "PAPI".)[31] A game theorist typically uses these elements, along with a solution concept of their choosing, to deduce a set of equilibrium strategies for each player such that, when these strategies are employed, no player can profit by unilaterally deviating from their strategy. These equilibrium strategies determine an equilibrium to the game—a stable state in which either one outcome occurs or a set of outcomes occur with known probability.

text: Most cooperative games are presented in the characteristic function form, while the extensive and the normal forms are used to define noncooperative games.

text: Extensive form[edit]

text: The extensive form can be used to formalize games with a time sequencing of moves. Games here are played on trees (as pictured here). Here each vertex (or node) represents a point of choice for a player. The player is specified by a number listed by the vertex. The lines out of the vertex represent a possible action for that player. The payoffs are specified at the bottom of the tree. The extensive form can be viewed as a multi-player generalization of a decision tree.[32] To solve any extensive form game, backward induction must be used. It involves working backwards up the game tree to determine what a rational player would do at the last vertex of the tree, what the player with the previous move would do given that the player with the last move is rational, and so on until the first vertex of the tree is reached.[33]

text: The game pictured consists of two players. The way this particular game is structured (i.e., with sequential decision making and perfect information), Player 1 "moves" first by choosing either F or U (Fair or Unfair). Next in the sequence, Player 2, who has now seen Player 1's move, chooses to play either A or R. Once Player 2 has made his/ her choice, the game is considered finished and each player gets their respective payoff. Suppose that Player 1 chooses U and then Player 2 chooses A: Player 1 then gets a payoff of "eight" (which in real-world terms can be interpreted in many ways, the simplest of which is in terms of money but could mean things such as eight days of vacation or eight countries conquered or even eight more opportunities to play the same game against other players) and Player 2 gets a payoff of "two".

text: The extensive form can also capture simultaneous-move games and games with imperfect information. To represent it, either a dotted line connects different vertices to represent them as being part of the same information set (i.e. the players do not know at which point they are), or a closed line is drawn around them. (See example in the imperfect information section.)

text: Normal form[edit]

text:
Player 2
chooses Left
Player 2
chooses Right

Player 1
chooses Up
4, 3
–1, –1

Player 1
chooses Down
0, 0
3, 4

Normal form or payoff matrix of a 2-player, 2-strategy game

text: The normal (or strategic form) game is usually represented by a matrix which shows the players, strategies, and payoffs (see the example to the right). More generally it can be represented by any function that associates a payoff for each player with every possible combination of actions. In the accompanying example there are two players; one chooses the row and the other chooses the column. Each player has two strategies, which are specified by the number of rows and the number of columns. The payoffs are provided in the interior. The first number is the payoff received by the row player (Player 1 in our example); the second is the payoff for the column player (Player 2 in our example). Suppose that Player 1 plays Up and that Player 2 plays Left. Then Player 1 gets a payoff of 4, and Player 2 gets 3.

text: When a game is presented in normal form, it is presumed that each player acts simultaneously or, at least, without knowing the actions of the other. If players have some information about the choices of other players, the game is usually presented in extensive form.

text: Every extensive-form game has an equivalent normal-form game, however the transformation to normal form may result in an exponential blowup in the size of the representation, making it computationally impractical.[34]

text: Characteristic function form[edit]

text: In games that possess removable utility, separate rewards are not given; rather, the characteristic function decides the payoff of each unity. The idea is that the unity that is 'empty', so to speak, does not receive a reward at all.

text:
The origin of this form is to be found in John von Neumann and Oskar Morgenstern's book; when looking at these instances, they guessed that when a union

C

{\displaystyle \mathbf {C} }

 appears, it works against the fraction

(

N

C

)

{\displaystyle \left({\frac {\mathbf {N} }{\mathbf {C} }}\right)}

 as if two individuals were playing a normal game. The balanced payoff of C is a basic function. Although there are differing examples that help determine coalitional amounts from normal games, not all appear that in their function form can be derived from such.

text:
Formally, a characteristic function is seen as: (N,v), where N represents the group of people and

v
:

2

N

→

R

{\displaystyle v:2^{N}\to \mathbf {R} }

 is a normal utility.

text: Such characteristic functions have expanded to describe games where there is no removable utility.

text: General and applied uses[edit]

text: As a method of applied mathematics, game theory has been used to study a wide variety of human and animal behaviors. It was initially developed in economics to understand a large collection of economic behaviors, including behaviors of firms, markets, and consumers. The first use of game-theoretic analysis was by Antoine Augustin Cournot in 1838 with his solution of the Cournot duopoly. The use of game theory in the social sciences has expanded, and game theory has been applied to political, sociological, and psychological behaviors as well.

text: Although pre-twentieth century naturalists such as Charles Darwin made game-theoretic kinds of statements, the use of game-theoretic analysis in biology began with Ronald Fisher's studies of animal behavior during the 1930s. This work predates the name "game theory", but it shares many important features with this field. The developments in economics were later applied to biology largely by John Maynard Smith in his book Evolution and the Theory of Games.[35]

text: In addition to being used to describe, predict, and explain behavior, game theory has also been used to develop theories of ethical or normative behavior and to prescribe such behavior.[36] In economics and philosophy, scholars have applied game theory to help in the understanding of good or proper behavior. Game-theoretic arguments of this type can be found as far back as Plato.[37]

text: Description and modeling[edit]

text: The primary use of game theory is to describe and model how human populations behave. Some[who?] scholars believe that by finding the equilibria of games they can predict how actual human populations will behave when confronted with situations analogous to the game being studied. This particular view of game theory has been criticized. It is argued that the assumptions made by game theorists are often violated when applied to real world situations. Game theorists usually assume players act rationally, but in practice, human behavior often deviates from this model. Game theorists respond by comparing their assumptions to those used in physics. Thus while their assumptions do not always hold, they can treat game theory as a reasonable scientific ideal akin to the models used by physicists. However, empirical work has shown that in some classic games, such as the centipede game, guess 2/3 of the average game, and the dictator game, people regularly do not play Nash equilibria. There is an ongoing debate regarding the importance of these experiments and whether the analysis of the experiments fully captures all aspects of the relevant situation.[38]

text: Some game theorists, following the work of John Maynard Smith and George R. Price, have turned to evolutionary game theory in order to resolve these issues. These models presume either no rationality or bounded rationality on the part of players. Despite the name, evolutionary game theory does not necessarily presume natural selection in the biological sense. Evolutionary game theory includes both biological as well as cultural evolution and also models of individual learning (for example, fictitious play dynamics).

text: Prescriptive or normative analysis[edit]

text:
Cooperate
Defect

Cooperate
-1, -1
-10, 0

Defect
0, -10
-5, -5

The Prisoner's Dilemma

text: Some scholars, like Leonard Savage,[citation needed] see game theory not as a predictive tool for the behavior of human beings, but as a suggestion for how people ought to behave. Since a strategy, corresponding to a Nash equilibrium of a game constitutes one's best response to the actions of the other players – provided they are in (the same) Nash equilibrium – playing a strategy that is part of a Nash equilibrium seems appropriate. This normative use of game theory has also come under criticism.

text: Economics and business[edit]

text: Game theory is a major method used in mathematical economics and business for modeling competing behaviors of interacting agents.[39] Applications include a wide array of economic phenomena and approaches, such as auctions, bargaining, mergers & acquisitions pricing,[40] fair division, duopolies, oligopolies, social network formation, agent-based computational economics,[41] general equilibrium, mechanism design,[42] and voting systems;[43] and across such broad areas as experimental economics,[44] behavioral economics,[45] information economics,[31] industrial organization,[46] and political economy.[47][48]

text: This research usually focuses on particular sets of strategies known as "solution concepts" or "equilibria". A common assumption is that players act rationally. In non-cooperative games, the most famous of these is the Nash equilibrium. A set of strategies is a Nash equilibrium if each represents a best response to the other strategies. If all the players are playing the strategies in a Nash equilibrium, they have no unilateral incentive to deviate, since their strategy is the best they can do given what others are doing.[49][50]

text: The payoffs of the game are generally taken to represent the utility of individual players.

text: A prototypical paper on game theory in economics begins by presenting a game that is an abstraction of a particular economic situation. One or more solution concepts are chosen, and the author demonstrates which strategy sets in the presented game are equilibria of the appropriate type. Naturally one might wonder to what use this information should be put. Economists and business professors suggest two primary uses (noted above): descriptive and prescriptive.[36]

text: Political science[edit]

text: The application of game theory to political science is focused in the overlapping areas of fair division, political economy, public choice, war bargaining, positive political theory, and social choice theory. In each of these areas, researchers have developed game-theoretic models in which the players are often voters, states, special interest groups, and politicians.

text: Early examples of game theory applied to political science are provided by Anthony Downs. In his book An Economic Theory of Democracy,[51] he applies the Hotelling firm location model to the political process. In the Downsian model, political candidates commit to ideologies on a one-dimensional policy space. Downs first shows how the political candidates will converge to the ideology preferred by the median voter if voters are fully informed, but then argues that voters choose to remain rationally ignorant which allows for candidate divergence. Game Theory was applied in 1962 to the Cuban missile crisis during the presidency of John F. Kennedy.[52]

text: It has also been proposed that game theory explains the stability of any form of political government. Taking the simplest case of a monarchy, for example, the king, being only one person, does not and cannot maintain his authority by personally exercising physical control over all or even any significant number of his subjects. Sovereign control is instead explained by the recognition by each citizen that all other citizens expect each other to view the king (or other established government) as the person whose orders will be followed. Coordinating communication among citizens to replace the sovereign is effectively barred, since conspiracy to replace the sovereign is generally punishable as a crime. Thus, in a process that can be modeled by variants of the prisoner's dilemma, during periods of stability no citizen will find it rational to move to replace the sovereign, even if all the citizens know they would be better off if they were all to act collectively.[53]

text: A game-theoretic explanation for democratic peace is that public and open debate in democracies send clear and reliable information regarding their intentions to other states. In contrast, it is difficult to know the intentions of nondemocratic leaders, what effect concessions will have, and if promises will be kept. Thus there will be mistrust and unwillingness to make concessions if at least one of the parties in a dispute is a non-democracy.[54]

text: On the other hand, game theory predicts that two countries may still go to war even if their leaders are cognizant of the costs of fighting. War may result from asymmetric information; two countries may have incentives to mis-represent the amount of military resources they have on hand, rendering them unable to settle disputes agreeably without resorting to fighting. Moreover, war may arise because of commitment problems: if two countries wish to settle a dispute via peaceful means, but each wishes to go back on the terms of that settlement, they may have no choice but to resort to warfare. Finally, war may result from issue indivisibilities.[55]

text: Game theory could also help predict a nation's responses when there is a new rule or law to be applied to that nation. One example would be Peter John Wood's (2013) research when he looked into what nations could do to help reduce climate change. Wood thought this could be accomplished by making treaties with other nations to reduce green house gas emissions. However, he concluded that this idea could not work because it would create a prisoner's dilemma to the nations.[56]

text: Biology[edit]

text:
Hawk
Dove

Hawk
20, 20
80, 40

Dove
40, 80
60, 60

The hawk-dove game

text: Unlike those in economics, the payoffs for games in biology are often interpreted as corresponding to fitness. In addition, the focus has been less on equilibria that correspond to a notion of rationality and more on ones that would be maintained by evolutionary forces. The best known equilibrium in biology is known as the evolutionarily stable strategy (ESS), first introduced in (Smith & Price 1973). Although its initial motivation did not involve any of the mental requirements of the Nash equilibrium, every ESS is a Nash equilibrium.

text: In biology, game theory has been used as a model to understand many different phenomena. It was first used to explain the evolution (and stability) of the approximate 1:1 sex ratios. (Fisher 1930) suggested that the 1:1 sex ratios are a result of evolutionary forces acting on individuals who could be seen as trying to maximize their number of grandchildren.

text: Additionally, biologists have used evolutionary game theory and the ESS to explain the emergence of animal communication.[57] The analysis of signaling games and other communication games has provided insight into the evolution of communication among animals. For example, the mobbing behavior of many species, in which a large number of prey animals attack a larger predator, seems to be an example of spontaneous emergent organization. Ants have also been shown to exhibit feed-forward behavior akin to fashion (see Paul Ormerod's Butterfly Economics).

text: Biologists have used the game of chicken to analyze fighting behavior and territoriality.[58]

text: According to Maynard Smith, in the preface to Evolution and the Theory of Games, "paradoxically, it has turned out that game theory is more readily applied to biology than to the field of economic behaviour for which it was originally designed". Evolutionary game theory has been used to explain many seemingly incongruous phenomena in nature.[59]

text: One such phenomenon is known as biological altruism. This is a situation in which an organism appears to act in a way that benefits other organisms and is detrimental to itself. This is distinct from traditional notions of altruism because such actions are not conscious, but appear to be evolutionary adaptations to increase overall fitness. Examples can be found in species ranging from vampire bats that regurgitate blood they have obtained from a night's hunting and give it to group members who have failed to feed, to worker bees that care for the queen bee for their entire lives and never mate, to vervet monkeys that warn group members of a predator's approach, even when it endangers that individual's chance of survival.[60] All of these actions increase the overall fitness of a group, but occur at a cost to the individual.

text: Evolutionary game theory explains this altruism with the idea of kin selection. Altruists discriminate between the individuals they help and favor relatives. Hamilton's rule explains the evolutionary rationale behind this selection with the equation c<b*r where the cost (c) to the altruist must be less than the benefit (b) to the recipient multiplied by the coefficient of relatedness (r). The more closely related two organisms are causes the incidences of altruism to increase because they share many of the same alleles. This means that the altruistic individual, by ensuring that the alleles of its close relative are passed on, (through survival of its offspring) can forgo the option of having offspring itself because the same number of alleles are passed on. Helping a sibling for example (in diploid animals), has a coefficient of ½, because (on average) an individual shares ½ of the alleles in its sibling's offspring. Ensuring that enough of a sibling’s offspring survive to adulthood precludes the necessity of the altruistic individual producing offspring.[60] The coefficient values depend heavily on the scope of the playing field; for example if the choice of whom to favor includes all genetic living things, not just all relatives, we assume the discrepancy between all humans only accounts for approximately 1% of the diversity in the playing field, a co-efficient that was ½ in the smaller field becomes 0.995. Similarly if it is considered that information other than that of a genetic nature (e.g. epigenetics, religion, science, etc.) persisted through time the playing field becomes larger still, and the discrepancies smaller.

text: Computer science and logic[edit]

text: Game theory has come to play an increasingly important role in logic and in computer science. Several logical theories have a basis in game semantics. In addition, computer scientists have used games to model interactive computations. Also, game theory provides a theoretical basis to the field of multi-agent systems.

text: Separately, game theory has played a role in online algorithms; in particular, the k-server problem, which has in the past been referred to as games with moving costs and request-answer games.[61] Yao's principle is a game-theoretic technique for proving lower bounds on the computational complexity of randomized algorithms, especially online algorithms.

text: The emergence of the internet has motivated the development of algorithms for finding equilibria in games, markets, computational auctions, peer-to-peer systems, and security and information markets. Algorithmic game theory[62] and within it algorithmic mechanism design[63] combine computational algorithm design and analysis of complex systems with economic theory.[64]

text: Philosophy[edit]

text:
Stag
Hare

Stag
3, 3
0, 2

Hare
2, 0
2, 2

Stag hunt

text: Game theory has been put to several uses in philosophy. Responding to two papers by W.V.O. Quine (1960, 1967), Lewis (1969) used game theory to develop a philosophical account of convention. In so doing, he provided the first analysis of common knowledge and employed it in analyzing play in coordination games. In addition, he first suggested that one can understand meaning in terms of signaling games. This later suggestion has been pursued by several philosophers since Lewis.[65] Following Lewis (1969) game-theoretic account of conventions, Edna Ullmann-Margalit (1977) and Bicchieri (2006) have developed theories of social norms that define them as Nash equilibria that result from transforming a mixed-motive game into a coordination game.[66][67]

text: Game theory has also challenged philosophers to think in terms of interactive epistemology: what it means for a collective to have common beliefs or knowledge, and what are the consequences of this knowledge for the social outcomes resulting from agents' interactions. Philosophers who have worked in this area include Bicchieri (1989, 1993),[68][69] Skyrms (1990),[70] and Stalnaker (1999).[71]

text: In ethics, some[who?] authors have attempted to pursue Thomas Hobbes' project of deriving morality from self-interest. Since games like the prisoner's dilemma present an apparent conflict between morality and self-interest, explaining why cooperation is required by self-interest is an important component of this project. This general strategy is a component of the general social contract view in political philosophy (for examples, see Gauthier (1986) and Kavka (1986)).[72]

text: Other authors have attempted to use evolutionary game theory in order to explain the emergence of human attitudes about morality and corresponding animal behaviors. These authors look at several games including the prisoner's dilemma, stag hunt, and the Nash bargaining game as providing an explanation for the emergence of attitudes about morality (see, e.g., Skyrms (1996, 2004) and Sober and Wilson (1999)).

text: In popular culture[edit]

text:
Based on the book by Sylvia Nasar,[73] the life story of game theorist and mathematician John Nash was turned into the biopic A Beautiful Mind starring Russell Crowe.[74]
"Games theory" and "theory of games" are mentioned in the military science fiction novel Starship Troopers by Robert A. Heinlein.[75] In the 1997 film of the same name, the character Carl Jenkins refers to his assignment to military intelligence as to "games and theory".
The film Dr. Strangelove satirizes game theoretic ideas about deterrence theory. For example, nuclear deterrence depends on the threat to retaliate catastrophically if a nuclear attack is detected. A game theorist might argue that such threats can fail to be credible, in the sense that they can lead to subgame imperfect equilibria. The movie takes this idea one step further, with the Russians irrevocably committing to a catastrophic nuclear response without making the threat public.[citation needed]
Liar Game is a popular Japanese manga, television program and movie, where each episode presents the main characters with a Game Theory type game. The show's supporting characters reflect and explore game theory's predictions around self-preservation strategies used in each challenge. The main character however, who is portrayed as an innocent, naive and good hearted young lady Kansaki Nao, always attempts to convince the other players to follow a mutually beneficial strategy where everybody wins. Kansaki Nao's seemingly simple strategies that appear to be the product of her innocent good nature actually represent optimal equilibrium solutions which Game Theory attempts to solve. Other players however, usually use her naivety against her to follow strategies that serve self-preservation. The show improvises heavily on Game Theory predictions and strategies to provide each episode's script, the players decisions. In a sense, each episode exhibits a Game Theory game and the strategies/ equilibria/ solutions provide the script which is coloured in by the actors.[citation needed]


document_title: Springfield, Illinois

question_text: when did springfield become the capital of illinois

question_tokens: when did springfield become the capital of illinois

root

text: Springfield, Illinois

text: History[edit]

text: Springfield's original name was Calhoun, after Senator John C. Calhoun of South Carolina.[12] The land that Springfield now occupies was originally settled by trappers and traders who came to the Sangamon River in 1818.[13] The settlement's first cabin was built in 1820, by John Kelly. It was located at what is now the northwest corner of Second Street and Jefferson Street. In 1821, Calhoun became the county seat of Sangamon County due to fertile soil and trading opportunities. Settlers from Kentucky, Virginia, and as far as North Carolina came to the city.[13] By 1832, Senator Calhoun had fallen out of the favor with the public and the town renamed itself Springfield after Springfield, Massachusetts. At that time, Springfield, Massachusetts was comparable to modern-day Silicon Valley—known for industrial innovation, concentrated prosperity, and the celebrated Springfield Armory. Most importantly, it was a city that had built itself up from frontier outpost to national power through ingenuity – an example that the newly named Springfield, Illinois, sought to emulate.[14] Kaskaskia was the first capital of the Illinois Territory from its organization in 1809, continuing through statehood in 1818, and through the first year as a state in 1819. Vandalia was the second state capital of Illinois from 1819 to 1839. Springfield became the third and current capital of Illinois in 1839. The designation was largely due to the efforts of Abraham Lincoln and his associates; nicknamed the "Long Nine" for their combined height of 54 feet (16 m).[13][14]

tag: p

text: The Potawatomi Trail of Death passed through here in 1838.

text: Lincoln[edit]

text: Lincoln and politics[edit]

text: Lincoln arrived in the Springfield area when he was a young man in 1831, though he would not actually live in the city until 1837.[15] He spent the ensuing six years in New Salem where he began his legal studies, joined the state militia and was elected to the Illinois General Assembly. In 1837 Lincoln moved to Springfield and spent the next 24 years as a lawyer and politician. Lincoln delivered his Lyceum address in Springfield. His farewell speech when he left for Washington is a classic in American oratory.[15]

text: Winkle (1998) examines the historiography concerning the development of the Second Party System (Whigs versus Democrats) and applies these ideas to the study of Springfield, a strong Whig enclave in a Democratic region, mainly by studying poll books for presidential years. The rise of the Whig Party took place in 1836 in opposition to the presidential candidacy of Martin Van Buren and was consolidated in 1840. Springfield Whigs tend to validate several expectations of party characteristics as they were largely native-born, either in New England or Kentucky, professional or agricultural in occupation, and devoted to partisan organization. Abraham Lincoln's career mirrors the Whigs' political rise, but by the 1840s Springfield began to fall into Democratic hands, as immigrants changed the city's political makeup. By the 1860 presidential election, Lincoln was barely able to win his home city.[16]

text: Population[edit]

text: Winkle (1992) examines the impact of migration on political participation in Springfield during the 1850s. Widespread migration in the 19th-century United States produced frequent population turnover within Midwestern communities, which influenced patterns of voter turnout and office-holding. Examination of the manuscript census, poll books, and office-holding records reveals the impact of migration on the behavior of 8,000 participants in 10 elections in Springfield. Most voters were short-term residents who participated in only one or two elections during the 1850s, and fewer than 1% of all voters participated in all 10 elections. Instead of producing political instability, however, rapid turnover enhanced the influence of more persistent residents. Migration was selective by age, occupation, wealth, and birthplace. Therefore, more persistent voters were wealthier, more highly skilled, more often native-born, and socially more stable than nonpersisters. Officeholders were particularly persistent and socially and economically advantaged. Persisters represented a small "core community" of economically successful, socially homogeneous, and politically active voters and officeholders who controlled local political affairs while most residents moved in and out of the city. Members of a tightly knit and exclusive "core community", exemplified by Abraham Lincoln, blunted the potentially disruptive impact of migration on local communities.[17] And the population as of 2013 is 117,006

text: Business[edit]

text: The case of John Williams illustrates the important role of the merchant banker in the economic development of central Illinois before the Civil War. Williams began his career as a clerk in frontier stores and saved to begin his own business. Later, in addition to operating retail and wholesale stores, he acted as a local banker and then organized a national bank in Springfield. He was active in railroad promotion and as an agent for farm machinery.[18]

text: Religion[edit]

text: During the mid-19th century, the spiritual needs of German Lutherans in the Midwest were not being tended. As a result of the efforts of such missionaries as Friedrich Wyneken, Wilhelm Loehe, and Wilhelm Sihler, this situation was remedied by the deployment of additional Lutheran ministers, the opening of Lutheran schools, and the creation in Ft. Wayne, Indiana of the Concordia Theological Seminary in 1846. The seminary moved to St. Louis, Missouri, in 1869, and then to Springfield in 1874. Through this seminary, during the last half of the 19th century and the first half of the 20th century, the Lutheran Church–Missouri Synod succeeded in serving the spiritual needs of Midwestern congregations by establishing additional seminaries, and by developing a viable synodical tradition.[19]

text: Civil War to 1900[edit]

text: The American Civil War made Springfield a major center of activity. Illinois regiments trained there, the first ones under Ulysses S. Grant, who marched his soldiers to a remarkable series of victories in 1861–62. The city was a political and financial center of support, and new industries, businesses, and railroads were constructed to help support the war effort.[14] The war's first official death was a Springfield resident, Colonel Elmer E. Ellsworth.

text: Camp Butler, seven miles (11 km) northeast of Springfield, Illinois, opened in August 1861 as a training camp for Illinois soldiers, but also served as a camp for Confederate prisoners of war through 1865. In the beginning, Springfield residents visited the camp to experience the excitement of a military venture, but many reacted sympathetically to mortally wounded and ill prisoners. While the city's businesses prospered from camp traffic, drunken behavior and rowdiness on the part of the soldiers stationed there strained relations as neither civil nor military authorities proved able to control disorderly outbreaks.[20]

text: After the war ended in 1865, Springfield became a major hub in the Illinois railroad system and besides politics and farming, coal mining was a major industry for Springfield by 1900.[14]

text: 20th century[edit]

text: Utopia[edit]

text: Local poet Vachel Lindsay's notions of utopia were expressed in his only novel, The Golden Book of Springfield (1920), which draws on ideas of anarchistic socialism in projecting the progress of Lindsay's hometown toward utopia.[21]

text: The Dana-Thomas House is a Frank Lloyd Wright design built in 1902–03. Wright began work on the house in 1902. Commissioned by Susan Lawrence Dana, a local patron of the arts and public benefactor, Wright designed a house to harmonize with the owner's devotion to the performance of music. Coordinating art glass designs for 250 windows, doors, and panels as well as over 200 light fixtures, Wright enlisted Oak Park artisans. The house is a radical departure from Victorian architectural traditions. Covering 12,000 square feet (1,100 m2), the house contained vaulted ceilings and 16 major spaces. As the nation was changing, so Wright intended this structure to reflect the changes. Creating an organic and natural atmosphere, Wright saw himself as an "architect of democracy" and intended his work to be a monument to America's social landscape.[22]

text: It is the only historic site later acquired by the state exclusively because of its architectural merit. The structure was opened to the public as a museum house in September 1990; tours are available, 9:00 a.m.–4:00 p.m. Wednesdays through Sundays.[22][23][24]

text: 1908 race riot[edit]

text: Sparked by the alleged rape of a white woman by a black man and the murder of a white engineer, supposedly also by a black man, in Springfield, and reportedly angered by the high degree of corruption in the city, some white residents took their anxiety and frustration out on blacks. Rioting broke out on August 14, 1908 and continued for three days in a period of violence known as the Springfield Race Riot. Gangs of white youth and blue-collar workers attacked the predominantly black areas of the city known as the Levee district, where most black businesses were located, and the Badlands, where many black residences stood. Two blacks were lynched and four whites were killed by gunfire when black property-owners sought to defend their homes and businesses. The riot ended when the governor sent in more than 3,700 militiamen to patrol the city, but isolated incidents of white violence against blacks continued in Springfield into September.[25]

text: 21st century[edit]

text: On March 12, 2006, two F2 tornadoes hit the city, injuring 24 people, damaging hundreds of buildings, and causing $150 million in damages.[26]

text: On February 10, 2007, then-senator Barack Obama announced his presidential candidacy in Springfield, standing on the grounds of the Old State Capitol.[27] Senator Obama also used the Old State Capitol in Springfield as a backdrop when he announced Joe Biden as his running mate on August 23, 2008.

text: Geography[edit]

text: Springfield is located at 39°41′54″N 89°37′11″W / 39.69833°N 89.61972°W / 39.69833; -89.61972 (39.6983146, -89.6195900).[9] The city is at an elevation of 558 feet (170 m) above sea level.[9] Located within the central section of Illinois, Springfield is 90 miles (140 km) northeast of St. Louis. The Champaign/Urbana area is to the east, Peoria is to the north, and Bloomington–Normal is to the northeast. Decatur is 40 miles (64 km) due east.

text: Topography[edit]

text: According to the 2010 census, Springfield has a total area of 65.764 square miles (170.33 km2), of which 59.48 square miles (154.05 km2) (or 90.44%) is land and 6.284 square miles (16.28 km2) (or 9.56%) is water.[28] The city is located in the Lower Illinois River Basin, in a large area known as Till Plain. Sangamon County, and the city of Springfield, are in the Springfield Plain subsection of Till Plain. The Plain is underlain by glacial till that was deposited by a large continental ice sheet that repeatedly covered the area during the Illinoian Stage.[29][30]

text: The majority of the Lower Illinois River Basin is flat, with relief extending no more than 20 feet (6.1 m) in most areas, including the Springfield subsection of the plain. The differences in topography are based on the age of drift. The Springfield and Galesburg Plain subsections represent the oldest drift, Illinoian, while Wisconsinian drift resulted in end moraines on the Bloomington Ridged Plain subsection of Till Plain.[31]

text: Lake Springfield is a 4,200-acre (1,700 ha) man-made reservoir owned by City Water, Light & Power,[32] the largest municipally owned utility in Illinois.[33] It was built and filled in 1935 by damming Lick Creek, a tributary of the Sangamon River which flows past Springfield's northern outskirts.[34] The lake is used primarily as a source for drinking water for the city of Springfield, also providing cooling water for the condensers at the power plant on the lake. It attracts approximately 600,000 visitors annually and its 57 miles (92 km) of shoreline is home to over 700 lakeside residences and eight public parks.[32]

text: The term "full pool" describes the lake at 560 feet (170.7 m) above sea level and indicates the level at which the lake begins to flow over the dam's spillway, if no gates are opened.[34] Normal lake levels are generally somewhere below full pool, depending upon the season. During the drought from 1953 to 1955, lake levels dropped to their historical low, 547.44 feet (166.86 m) AMSL.[34] The highest recorded lake levels were in December 1982, when the lake crested at 564 feet (172 m).[34]

text: Climate[edit]

text:
[show]Climate data for Springfield, Illinois (Capital Airport), 1981–2010 normals

Month
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Year

Record high °F (°C)
73
(23)
78
(26)
91
(33)
90
(32)
101
(38)
104
(40)
112
(44)
108
(42)
102
(39)
93
(34)
83
(28)
74
(23)
112
(44)

Average high °F (°C)
34.8
(1.6)
39.9
(4.4)
52.1
(11.2)
64.6
(18.1)
74.8
(23.8)
83.1
(28.4)
86.2
(30.1)
84.9
(29.4)
78.9
(26.1)
66.4
(19.1)
52.3
(11.3)
38.3
(3.5)
63.1
(17.3)

Average low °F (°C)
18.7
(−7.4)
22.6
(−5.2)
32.2
(0.1)
42.4
(5.8)
52.6
(11.4)
61.9
(16.6)
65.4
(18.6)
63.6
(17.6)
54.6
(12.6)
43.8
(6.6)
33.9
(1.1)
22.5
(−5.3)
43.0
(6.1)

Record low °F (°C)
−22
(−30)
−24
(−31)
−12
(−24)
17
(−8)
28
(−2)
39
(4)
48
(9)
43
(6)
31
(−1)
13
(−11)
−3
(−19)
−21
(−29)
−24
(−31)

Average precipitation inches (mm)
1.82
(46.2)
1.81
(46)
2.63
(66.8)
3.51
(89.2)
4.24
(107.7)
4.46
(113.3)
3.94
(100.1)
3.24
(82.3)
2.90
(73.7)
3.15
(80)
3.21
(81.5)
2.52
(64)
37.43
(950.8)

Average snowfall inches (cm)
6.4
(16.3)
5.5
(14)
2.5
(6.4)
0.3
(0.8)
0.0
(0)
0.0
(0)
0.0
(0)
0.0
(0)
0.0
(0)
Trace
0.6
(1.5)
5.6
(14.2)
20.9
(53.1)

Average precipitation days (≥ 0.01 in)
9.1
8.1
10.7
11.3
11.7
10.2
8.6
8.3
7.4
8.5
9.6
9.9
113.4

Average snowy days (≥ 0.1 in)
5.4
3.9
1.9
0.3
0.0
0.0
0.0
0.0
0.0
0.1
0.8
4.5
16.9

Average relative humidity (%)
73.4
74.0
71.3
65.3
65.6
66.6
70.4
74.0
71.9
68.4
73.8
77.6
71.0

Mean monthly sunshine hours
160.7
158.7
186.5
225.8
281.2
308.0
320.7
291.0
248.4
214.0
140.2
129.3
2,664.5

Percent possible sunshine
53
53
50
57
63
69
70
68
66
62
47
44
60

Source: NOAA (extremes 1879–present, sun and relative humidity 1961–1990)[35][36][37]

tag: table

text: Springfield has a humid continental climate (Köppen Dfa) and experiences typical mid-latitude weather. Hot, humid summers and cold, rather snowy winters are the norm. Springfield is located in Tornado Alley and experiences large numbers of tornadoes. From 1961 to 1990 the city of Springfield averaged 35.25 inches (895 mm) of precipitation per year.[38] During that same period the average yearly temperature was 52.4 °F (11.3 °C), with a summer maximum of 76.5 °F (24.7 °C) in July and a winter minimum of 24.2 °F (−4.3 °C) in January.[39]

text: From 1971 to 2000, NOAA data showed that Springfield's annual mean temperature increased slightly to 52.7 °F (11.5 °C). During that period, July averaged 76.3 °F (24.6 °C), while January averaged 25.1 °F (−3.8 °C).

text: On June 14, 1957, a tornado hit Springfield, killing two people.[26] On March 12, 2006, the city was struck by two F2 tornadoes.[26] The storm system which brought the two tornadoes hit the city around 8:30pm; no one died as a result of the weather.[26] Springfield received a federal grant in February 2005 to help improve its tornado warning systems and new sirens were put in place in November 2006 after eight of the sirens failed during an April 2006 test, shortly after the tornadoes hit.[40][41][42] The cost of the new sirens totaled $983,000.[40] Although tornadoes are not uncommon in central Illinois, the March 12 tornadoes were the first to hit the actual city since the 1957 storm.[26] The 2006 tornadoes followed nearly identical paths to that of the 1957 tornado.[26]

text: Demographics[edit]

text:
Historical population

Census
Pop.

%±

1840
2,579

—

1850
4,533

75.8%

1860
9,320

105.6%

1870
17,364

86.3%

1880
19,743

13.7%

1890
24,963

26.4%

1900
34,159

36.8%

1910
51,678

51.3%

1920
59,183

14.5%

1930
71,864

21.4%

1940
75,503

5.1%

1950
81,628

8.1%

1960
83,271

2.0%

1970
91,753

10.2%

1980
99,637

8.6%

1990
105,227

5.6%

2000
111,454

5.9%

2010
116,250

4.3%

Est. 2016
115,715
[6]
−0.5%

U.S. Decennial Census[43]

text: At the 2010 Census, 75.8% of the population was White, 18.5% Black or African American, 0.2% American Indian and Alaska Native, 2.2% Asian, and 2.6% of two or more races. 2.0% of Springfield's population was of Hispanic or Latino origin (they may be of any race).[5] Non-Hispanic Whites were 74.7% of the population in 2010,[5] down from 87.6% in 1980.[44]

text: As of the census[45] of 2000,[needs update] there were 111,454 people, 48,621 households, and 27,957 families residing in the city. The population density was 2,063.9 people per square mile (796.9/km²). There were 53,733 housing units at an average density of 995.0 per square mile (384.2/km²). The racial makeup of the city was 81.0% White, 15.3% African American, 0.2% Native American, 1.5% Asian, 0.1% Pacific Islander, 0.5% from other races, and 1.5% from two or more races. Hispanic or Latino of any race were 1.2% of the population.

text: There were 48,621 households, out of which 27.5% had children under the age of 18 living with them, 41.1% were married couples living together, 12.9% had a female householder with no husband present, and 42.5% were non-families. 36.1% of all households were made up of individuals and 11.7% had someone living alone who was 65 years of age or older. The average household size was 2.24 and the average family size was 2.94.

text: In the city, the population was spread out, with 28.0% under the age of 18, 8.8% from 18 to 24, 29.8% from 25 to 44, 23.0% from 45 to 64, and 14.4% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 88.6 males. For every 100 females age 18 and over, there were 86.6 males.

text: The median income for a household in the city was $39,388, and the median income for a family was $51,298. Families with children had a higher income of about $69,437. Males had a median income of $36,864 versus $28,867 for females. The per capita income for the city was $23,324. About 8.4% of families and 11.7% of the population were below the poverty line, including 17.3% of those under age 18 and 7.7% of those age 65 or over.

text: Cityscape[edit]

text: Springfield proper is greatly based on a grid street system, with numbered streets starting with the longitudinal First Street which leads to the Illinois State Capitol and leading to 32nd Street in the far eastern part of the city. Previously the city had four distinct boundary streets: North, South, East, and West Grand Avenues. Since expansion, West Grand Avenue became MacArthur Boulevard and East Grand became 19th Street on the north side and 18th Street on the south side. 18th Street has since been renamed after Martin Luther King Jr. North and South Grand Avenues (which run east–west) have remained important corridors in the city. At South Grand and Eleventh Street, the old "South Town District" lies, with the City of Springfield undertaking a significant redevelopment project there.

text: Latitudinal streets range from names of presidents in the downtown area to names of notable people in Springfield and Illinois to names of institutions of higher education, especially in the Harvard Park neighborhood.

text: Springfield has at least twenty separately designated neighborhoods, though not all are incorporated with associations. They include: Benedictine District, Bunn Park, the Cabbage Patch, Downtown, Eastsview, Enos Park, Glen Aire, Harvard Park, Hawthorne Place, Historic West Side, Laketown, Lincoln Park, Mather and Wells, Medical District, Near South, Northgate, Oak Ridge, Old Aristocracy Hill, Pillsbury District, Shalom, Springfield Lakeshore, Toronto, Twin Lakes, UIS Campus, Victoria Lake, Vinegar Hill, and Westchester neighborhoods.[46]

text: The Lincoln Park Neighborhood is an area bordered by 3rd Street on its west, Black Avenue on the north, 8th street on the east and North Grand Avenue. The neighborhood is not far from Lincoln's Tomb on Monument Avenue.[47]

text: Springfield also encompasses four different suburban villages that have their own municipal governments. They include Jerome, Leland Grove, Southern View and Grandview.

text: Culture[edit]

text: Springfield has been home to a wide array of individuals, who, in one way or another, contributed to the broader American culture. Wandering poet Vachel Lindsay, most famous for his poem "The Congo" and a booklet called "Rhymes to be Traded for Bread", was born in Springfield in 1879.[48] At least two notable people affiliated with American business and industry have called the Illinois state capital home at one time or another. Both John L. Lewis, a labor activist, and Marjorie Merriweather Post, the founder of the General Foods Corporation, lived in the city; Post in particular was a native of Springfield.[49][50] In addition, astronomer Seth Barnes Nicholson was born in Springfield in 1891.[51]

text: Literary tradition[edit]

text: Springfield and the Sangamon Valley enjoy a strong literary tradition in Abraham Lincoln, Vachel Lindsay, Edgar Lee Masters, John Hay, William H. Herndon, Benjamin P. Thomas, Paul Angle, Virginia Eiffert, Robert Fitzgerald and William Maxwell, among others. The Illinois State Library's Gwendolyn Brooks Building features the names of 35 Illinois authors etched on its exterior fourth floor frieze. Through the Illinois Center for the Book, a comprehensive resource on authors, illustrators, and other creatives who have published books who have written about Illinois or lived in Illinois is maintained.[52]

text: Performing arts[edit]

text: The Hoogland Center for the Arts in downtown Springfield is a centerpiece for performing arts, and houses among other organizations the Springfield Theatre Centre, the Springfield Ballet Company, the Illinois Symphony Orchestra[53] and the Springfield Municipal Opera, also known as The Muni, which stages community theatre productions of Broadway musicals outdoors each summer. Before being purchased and renamed, the Hoogland Center was Springfield's Masonic Temple. Prior to the Hoogland, the Springfield Theatre Centre was housed in the nearby Legacy Theatre. Sangamon Auditorium, located on the campus of the University of Illinois at Springfield also serves as a larger venue for musical and performing acts, both touring and local.

text: A few films have been created or had elements of them created in Springfield. Legally Blonde 2: Red, White & Blonde was filmed in Springfield in 2003.

text: Musicians Artie Matthews and Morris Day both once called Springfield home.[54][55] Other performing arts such as music and ballet are also common in Springfield.[56][57]

text: Springfield is also home to long running underground all-ages space The Black Sheep Cafe.[58]

text: Festivals[edit]

text: Springfield is home to the annual Springfield Old Capitol Art Fair, a spring festival held annually in the third weekend in May.[59] Since 2002, Springfield has also hosted the 'Route 66 Film Festival', set to celebrate films routed in, based on, or taking part on the famous Route 66.[60][61][62]

text: Tourism[edit]

text: Springfield is known for some popular food items: the corn dog is claimed to have been invented in the city under the name "Cozy Dog", although there is some debate to the origin of the snack.[63][64] The horseshoe sandwich, not well known outside of central Illinois, also originated in Springfield.[65] Springfield was once the site of the Reisch Beer brewery, which operated for 117 years under the same name and family from 1849 to 1966.[66]

text: The Maid-Rite Sandwich Shop in Springfield still operates what it claims as the first U.S. drive-thru window.[67] The city is also known for its chili, or "chilli", as it is known in many chili shops throughout Sangamon County.[68] The unique spelling is said to have begun with the founder of the Dew Chilli Parlor in 1909, due to a spelling error in its sign.[69] Another interpretation is that the misspelling represented the "Ill" in the word Illinois.[69] In 1993, the Illinois state legislature adopted a resolution proclaiming Springfield the "Chilli Capital of the Civilized World."[68]

text: Springfield is dotted with sites associated with U.S. President Abraham Lincoln, who started his political career there.[70] These include the Lincoln Home National Historic Site, a National Historical Park that includes the preserved surrounding neighborhood; the Lincoln-Herndon Law Offices State Historic Site, the Lincoln Tomb State Historic Site, the Old State Capitol State Historic Site, the Lincoln Depot, from which Abraham Lincoln departed Springfield to be inaugurated in Washington, D.C.; the Elijah Iles House, Edwards Place and the Abraham Lincoln Presidential Library and Museum. Near the village of Petersburg, is New Salem State Park, a restored hamlet of log cabins. This is a reconstruction of the town where Lincoln lived as a young man. With the opening of the Presidential Library and Museum in 2004, the city has attracted numerous prominent visitors, including Presidents George W. Bush and Barack Obama, the actor Liam Neeson, and the Emir of Qatar.[71][72]

text: The Donner Party, a group of pioneers who resorted to cannibalism while snowbound during a winter in the Sierra Nevada Mountains, began their journey West from Springfield.[73] Springfield's Dana-Thomas House is among the best preserved and most complete of Frank Lloyd Wright's early "Prairie" houses.[74] It was built in 1902–1904 and has many of the furnishings Wright designed for it.[74] Springfield's Washington Park is home to Thomas Rees Memorial Carillon and the site of a carillon festival, held annually since 1962.[75] In August, the city is the site of the Illinois State Fair.

text: Although not born in Springfield, Lincoln is the city's most famous resident. He lived there for 24 years.[15] The only home he ever owned is open to the public, seven days a week, free of charge, and operated by the National Park Service.[15]

text: Springfield has the area's largest amusement park, Knight's Action Park and Caribbean Water Park, which is open from May to September. The park also features and operates the city's only remaining drive-in theater, the Route 66 Twin Drive-In.

text: Sports[edit]

text:
team
League
Sport
Venue
Established
Championships

Springfield Jr. Blues
North American Hockey League
Ice Hockey
Nelson Center
1993
2

Springfield Sliders
Prospect League
Baseball
Robin Roberts Stadium
2008
1

Capital City Hooligans
Men's Roller Derby Association
Men's Roller Derby
Skateland South
2012
N/A

text: Historically, Springfield has been home to a number of minor league baseball franchises, the latest club, the college-prep Springfield Sliders, arriving in the city in 2008. In the 1948 baseball season, Springfield was also home to an All-American Girls Professional Baseball League team, the Springfield Sallies, but the team's lackluster performance led them to be folded in with the Chicago Colleens as rookie development teams the following year.

text: The city was the home of the Springfield Stallions, an indoor football team who played at the Prairie Capital Convention Center in 2007. Today, the city is host to the Springfield Jr. Blues, a North American Hockey League team that plays at the Nelson Recreation Center. The city is also a host to several Semi Pro Football Teams. The oldest organization is the Capital City Outlaws, which was established in 1992. The Outlaws which played 11 man football, most recently in The Midwest Football League until 2004, switched to an 8-man Semi Pro Football League (8FL) in 2004. The Sangamon County Seminoles became an expansion team in the 8FL in 2008. A newly formed team in 2010, the Springfield Foxes, play in the Mid States Football League (MSFL) (11 man). The Foxes were league runners-up in the MSFL League Championship in 2012.

text: The city has produced several notable professional sports talents. Current and former Major League Baseball players Kevin Seitzer, Jeff Fassero, Ryan O'Malley, Jason and Justin Knoedler, and Hall of Famer Robin Roberts were all born in Springfield.[76][77][78][79] Springfield's largest baseball field, Robin Roberts Stadium at Lanphier Park, takes its full name in honor of Roberts and his athletic achievements. Former MLB player Dick "Ducky" Schofield is currently an elected official in Springfield, and his son Dick also played in the Major Leagues, as does Ducky's grandson, Jayson Werth. Ducky, Dick, and Jayson were all born in Springfield. Ducky's daughter (and Jayson's mother) Kim Schofield Werth, also from Springfield, is a track star who competed in the U.S. Olympic Trials. National Basketball Association players Dave Robisch, Kevin Gamble, and Andre Iguodala are all from the city.[80][81] Long-time NFL announcer (NBC) and former Cincinnati Bengal Pro Bowl tight end Bob Trumpy is a city native, having graduated from Springfield High School. Former NFL wide receiver Otto Stowe was a 1967 graduate of the now-defunct Feitshans High School. A UFC fighter, Matt Mitrione, attended and played football for Sacred Heart Griffin. He also played in the NFL as an undrafted free agent.

text: At the 2016 Olympics in Rio de Janeiro, Brazil, Springfield native Ryan Held won a gold medal as a member of the USA 400-meter (4 X 100 meter) freestyle relay team along with Caeleb Dressel, Michael Phelps, and Nathan Adrian. During his senior year at Sacred-Heart Griffin High School in 2014, Held was named Illinois State Swimmer of the Year.[82]

text: Media[edit]

text: The State Journal-Register is the primary daily newspaper for Springfield, and its surrounding area. The newspaper was founded in 1831 as the Sangamon Journal, and claims to be "the oldest newspaper in Illinois."[citation needed] The local alternative weekly is the Illinois Times.

text: Springfield is part of the Springfield-Decatur-Champaign TV market.[83] Four TV stations broadcast from the Springfield area: WCIX MYTV 49, WICS ABC 20, WRSP FOX 55, and WSEC PBS 14. Springfield is also served by two stations in Decatur, WAND NBC 17 and WBUI CW 23, and two stations in Champaign, WCIA CBS 3 and WILL PBS 12. One television station that has since ceased to exist was WJJY-TV, which operated in the Springfield area for three years (1969–1971).[84]

text: The following radio stations broadcast in the Springfield area:

text:
WQNA 88.3 FM
WLUJ 89.7 FM
WSCT 90.5 FM
WUIS 91.9 FM
WUSW 92.7 FM
WQQL 93.9 FM
WCVS 96.7 FM
WQLZ 97.7 FM
WNNS 98.7 FM
WXAJ 99.7 FM
WYMG 100.5 FM
WLFZ 101.9 FM
WDBR 103.7 FM
WFMB-FM 104.5 FM.
WMAY 970 AM
WTAX 1240 AM/107.5 FM
WFMB 1450 AM
WCIC 90.5 FM

tag: ul

text: Springfield is home to the first city specific emoji keyboard in the world that includes images for news, events, deals and business listings. Springfield Emojis, also includes images for Abraham Lincoln, the Dana Thomas house, numerous other landmarks, and the world famous horseshoe.

text: NOAA Weather Radio[edit]

text: NOAA Weather Radio station WXJ75 transmits from Mechanicsburg and is licensed to NOAA's National Weather Service Central Illinois Weather Forecast Office at Lincoln, broadcasting on a frequency of 162.400 mHz (channel 1 on most newer weather radios, and most SAME weather radios). The station activates the SAME tone alarm feature and a 1050 Hz tone activating older radios (except for AMBER Alerts, using the SAME feature only) for hazardous weather and non-weather warnings and emergencies, along with selected weather watches, for the Illinois counties of Cass, Christian, DeWitt, Logan, Macon, Macoupin, Mason, Menard, Montgomery, Morgan, and Sangamon. Weather permitting, a tone alarm test of both the SAME and 1050 Hz tone features are conducted every Wednesday between 11 AM and Noon.[87]

text: Economy[edit]

text: Many of the jobs in the city center around state government, headquartered in Springfield. As of 2002, the State of Illinois is both the city and county's largest employer, employing 17,000 people across Sangamon County.[88] As of February 2007, government jobs, including local, state and county, account for about 30,000 of the city's non-agricultural jobs.[89] Trade, transportation and utilities, and the health care industries each provide between 17,000 and 18,000 jobs to the city.[89] The largest private sector employer in 2002 was Memorial Health System. 3,400 people worked for that company.[88] According to estimates from the "Living Wage Calculator", maintained by Pennsylvania State University, the living wage for the city of Springfield is $7.89 per hour for one adult,[90] approximately $15,780 working 2,000 hours per year. For a family of four, costs are increased and the living wage is $17.78 per hour within the city.[90] According to the United States Department of Labor's Bureau of Labor Statistics (BLS), the Civilian Labor force dropped from 116,500 in September 2006 to 113,400 in February 2007. In addition, the unemployment rate rose during the same time period from 3.8% to 5.1%.[89]

text: Largest employers[edit]

text: According to the City's 2015 Comprehensive Annual Financial Report,[91] the largest employers in the city are:

text:
#
Employer
# of Employees

1
State of Illinois
17,500

2
Memorial Medical Center
5,854

3
St. John's Hospital
3,096

4
Springfield Public Schools
2,095

5
Springfield Clinic LLP
2,039

6
Southern Illinois University School of Medicine
1,511

7
City of Springfield
1,467

8
BlueCross BlueShield
1,316

9
Horace Mann Educators Corporation
1,063

10
University of Illinois at Springfield
926

text: Law and government[edit]

text: Springfield city government is structured under the mayor-council form of government. It is the strong mayor variation of that type of municipal government, the mayor holds executive authority, including veto power, in Springfield.[92] The executive branch also consists of 17 non-elected city "offices." Ranging from the police department to the Office of Public Works, each office can be altered through city ordinance.[92]

text: Elected officials in the city, mayor, aldermen, city clerk, and treasurer, serve four-year terms.[93] The elections are not staggered.[93] The council members are elected from ten districts throughout the city while the mayor, city clerk and city treasurer are elected on an at-large basis.[93] The council, as a body, consists of the ten aldermen and the mayor, though the mayor is generally a non-voting member who only participates in the discussion.[94] There are a few instances where the mayor does vote on ordinances or resolutions: if there is a tie vote, if more than half of the aldermen support the motion, whether there is a tie or not, and where a vote greater than the majority is required by the municipal code.[94]

text: State government[edit]

text: As the state capital, Springfield, is home to the three branches of Illinois government. Much like the United States federal government, Illinois government has an executive branch, occupied by the state governor, a legislative branch, which consists of the state senate and house, and a judicial branch, which is topped by the Illinois Supreme Court.[95] The Illinois legislative branch is collectively known as the Illinois General Assembly.[96] Many State of Illinois bureaucrats work in offices in Springfield, and it is the regular meeting place of the Illinois General Assembly.[97] All persons elected in a statewide manner in Illinois are required to have at least one residence in Springfield, and the state government funds these residents.[98]

text: As of 2014[update] none of the major constitutional officers in the State of Illinois designated Springfield as their primary residence; most cabinet officers and all major constitutional officers instead primarily do their business in Chicago. A former director of the Southern Illinois University Paul Simon Institute for Public Affairs, Mike Lawrence, stated that many of the elected officials in Illinois "spend so little time in Springfield".[98] In 2012 St. Louis Post-Dispatch columnist Pat Gauen argued that because major state politicians such as the Governor of Illinois, as well as the Attorney General, Speaker of the House, the minority leader of the House, President of the Senate, the minority leader of the Senate, the Comptroller, and the Treasurer, all live in the Chicago area; because they work from the James R. Thompson Center in Chicago and that "Everybody who's anybody in Illinois government has an office in Chicago"; and because in March 2011 Governor Pat Quinn only spent a 68-day, 40 night period in Springfield as per his official schedule, "in the reality of Illinois politics, [Springfield] shares de facto capital status with Chicago."[97] University of Illinois researcher and former member of the Illinois legislature Jim Nowlan stated "It's almost like Chicago is becoming the shadow capital of Illinois" and that "Springfield is almost become a hinterland outpost."[98] Lawrence criticized the fact that state officials spent little time in Springfield since it estranged them from and devalued Illinois state employees based in that city.[98]

text: According to Gauen, "Illinois seems rather unlikely to move its official capital to Chicago".[97]

text: Township[edit]

text: The Capital Township formed from Springfield Township on July 1, 1877, and was established and named by the Sangamon County Board on March 6, 1878, and the limits of the township and City of Springfield were made co-extensive on February 17, 1892 to better serve the people. There are three functions of this township: assessing property, collection first property tax payment, and assisting residents that live in the township. One thing that makes the Capital township unique is that the township never has to raise taxes for road work, since the roads are maintained by the Springfield Department of Public Works.[99][100]

text: Education[edit]

text: Springfield is currently home to six public and private high schools.

text: The Springfield public school district is District No. 186. District 186 operates 24 elementary schools and an early learning center, (pre-K). District 186 operates three high schools, Lanphier High School, Springfield High School and Springfield Southeast High School, which replaced Feitshans High School in 1967, and five middle schools.[101]

text: Springfield's Sacred Heart-Griffin High School is a city Catholic high school.[102] Other area high schools include Calvary Academy and Lutheran High School.[103] Ursuline Academy was a second Catholic high school founded in 1857, first as an all-girls school, and converted to co-ed in 1981. The school was closed in 2007.

text: Springfield hosts three Universities. One is the University of Illinois at Springfield (UIS, formerly Sangamon State University), which is located on the southeast side of the city. The second is Benedictine University at Springfield located on North Fifth Street (formerly known as Springfield College in Illinois), and the third is Robert Morris University (Illinois), located on Montvale, just off Wabash.

text: Springfield is also home to a junior college Lincoln Land Community College, located just south of UIS. From 1875 to 1976, Springfield was also home to Concordia Theological Seminary. The seminary was moved back to its original home of Fort Wayne, Indiana, and the campus now serves as the Illinois Department of Corrections Academy.

text: The city is home to the Springfield campus of the Southern Illinois University School of Medicine,[104] which includes a Cancer Institute in Springfield's Medical District.[105]

text: Infrastructure[edit]

text: Health systems[edit]

text: There are two Springfield hospitals, Memorial Medical Center and St. John's Hospital. A third hospital, originally Springfield Community Hospital, and later renamed Doctor's Hospital operated on Springfield's south side until 2003.[106] Kindred Healthcare opened a long term acute care hospital in Springfield in 2010, however, the facility was purchased by Vibra Healthcare in 2013, and is now operated by Vibra under the name Vibra Hospital of Springfield.[107]

text: St. John's Hospital is home to the Prairie Heart Institute, which performs more cardiovascular procedures than any other hospital in Illinois.[108] The dominant health care providers in the area are SIU HealthCare and Springfield Clinic. The major medical education concern in the area is the Southern Illinois University School of Medicine. The major regional cancer center is the SIU Simmons Cancer Institute.

text: Parks[edit]

text: The Springfield Park District operates more than 30 parks throughout the city. The two best-known are Carpenter Park, an Illinois Nature Preserve on the banks of the Sangamon River, and Washington Park and Botanical Garden on the city's southwest side and adjacent to some of Springfield's most beautiful and architecturally interesting homes. Washington Park has also been home to the Thomas Rees Memorial Carillon since its dedication in 1962. Southwind Park, on the southern edge of the city, has been developed as a park enjoying full compliance with the Americans with Disabilities Act of 1990. Lincoln Park, located next to Oak Ridge Cemetery where President Lincoln's tomb is located, is home to the Nelson Recreation Center, which boasts a public swimming pool, tennis courts, and the city's only public ice rink, home of the Springfield Jr. Blues, a minor league hockey team. Centennial Park, which rests on the outskirts of Springfield's southwest limits, holds the city's only public skatepark, as well as several ball fields, tennis courts, and a manmade hill for cardio exercises and sledding in winter months.

text: In addition to the public-sector parks operated by the Springfield Park District, two significant privately operated tree gardens/arboretums operate within city limits: the Abraham Lincoln Memorial Garden on Lake Springfield south of the city, and the Adams Wildlife Sanctuary on Springfield's east side.

text: Public utilities[edit]

text: The owner of Lake Springfield, City Water, Light & Power, supplies electric power generated from the Dallman Power Plants for the city of Springfield and eight surrounding communities, the company also provides the cities and towns with water from the lake. In 2005, ground was broken for a third municipally owned power plant. This Power Plant has been completed and came online in 2009. Natural gas is provided via AmerenCILCO, formerly Central Illinois Light Company (CILCO).[109]

text: Transportation[edit]

text: Interstate 55 runs from north to south past Springfield, while I-72, which is concurrent with US 36 from the Missouri state line to Decatur, runs from east to west. Springfield is also served by Amtrak passenger trains, which operate between Chicago and St. Louis and stop at the former Gulf, Mobile & Ohio station.[110] Springfield is also served by Greyhound lines at a station on North Dirksen Parkway. Local mass transportation needs are met by a bus service. The Sangamon Mass Transit District (SMTD) operates Springfield's bus system.[111] The city also lies along historic Route 66.

text: Border thoroughfare traffic is handled by Veterans Parkway and J. David Jones Parkway on the west side, Everett M. Dirksen Parkway on the east side, Sangamon Avenue on the north end, and Wabash Avenue, Stanford Avenue, and Adlai Stevenson Drive on the south end. The far south corridor is served by Toronto and Woodside Roads. Thoroughfare traffic through the heart of the city is provided by a series of one-way streets. Fifth and Sixth Streets serve the bulk of the north–south traffic, with Fourth and Seventh Streets serving additional traffic between North Grand and South Grand Avenues. East-west traffic is handled by Jefferson Street, entering Springfield on the west side from IL 97, and then splitting into a pair of one-way streets at Amos Avenue (Madison eastbound and Jefferson westbound).The two converge again after Eleventh Street to become Clearlake Avenue, which in turn converges into I-72 eastbound just past Dirksen Parkway. Additional east–west one-way streets run through the downtown areas of Springfield, including Monroe, Adams, Washington, and Cook Streets, as well as a stretch of Lawrence Avenue.

text: Abraham Lincoln Capital Airport serves the capital city with scheduled passenger jet service to Chicago/O'Hare, Dallas-Fort Worth, Fort Myers (via the Punta Gorda Airport) and Orlando (via the Sanford Airport).[112]

text: Springfield and the surrounding metropolitan area has constructed bike trails and bike lanes on a number of streets. Currently four main trails exist; two significant paved trails, the Interurban Trail and the Lost Bridge Trail, serve Springfield and its suburbs of Chatham, Illinois and Rochester, Illinois respectively. The Lost Bridge Trail has been extended further into Springfield by the Bunn to Lost Bridge Trail, which follows a stretch of Ash Street and Taylor Avenue. Plans are to extend it further still to Stanford Avenue.[113] A third trail, the Wabash Trail, extends westward from the northern end of the Interurban Trail toward Parkway Pointe, a regional shopping destination.

text: The fourth trail is a section, opened in July 2011, of the Sangamon Valley Trail spanning north to south through the west central part of Sangamon County. The section open as of 2011 extends northward from Centennial Park to Stuart Park.[114] This trail, if completed in its entirety, will reuse the entire Sangamon County portion of the abandoned St. Louis, Peoria and North Western Railway railroad line as a trail that will extend from Girard, Illinois, to Athens, Illinois.

text: Notable people[edit]

text: Sister cities[edit]

text: Springfield, Illinois, USA has five sister cities, as designated by Sister Cities International, they include the following places:

text:
Astaneh-ye Ashrafiyeh (Iran)
 Villach (Austria)
 Killarney (Ireland)
 San Pedro (Mexico)
 Ashikaga (Japan)