Redistricting Game: This game allows students to re-draw district boundaries based on their party's interests, economic considerations, and legal restrictions.
Argument Wars: This game by icivics engages students in specific Supreme Court cases by asking them to cite support from previous cases. Students may pick avatars and otherwise personalize the game.
iCivics Games: A series of games related to civic engagement including Bill of Rights, Court Systems, Voting Regulations, and much more. Highly engaging and dynamic while also standards-driven.
1066: This strategy game based on the Battle of Hastings combines historical information with graphics more typical of recreational digital games.
See many other gaming options for history at http://playinghistory.org/