- For other uses, see Chicago.
During the early part of the 1920s, organized crime became a powerful fixture in the city of Chicago, to the point that conventional city government nearly fell apart. In the early 1990s, Pocket Books published a book titled Chicago Mobs of the Twenties, detailing the history of the Mob during that time period. A copy of the book later was left on the planet Sigma Iotia II by the Earth ship USS Horizon. The Iotians saw the society depicted in the book as a perfect society, and rebuilt their society along those lines. (TOS episode: "A Piece of the Action")
In 2251, James T. Kirk guessed that Gary Mitchell was either from Chicago or Detroit. He was wrong on both counts, as Mitchell was born and raised in New York City. (TOS - My Brother's Keeper novel: Republic)
In the mirror universe, Chicago was one of the cities devastated in a brazen attack by alien rebels against the Terran Empire in 2155. Empress Sato I visited Chicago following the attacks, where she was surprised to find the citizens' anger directed at her. (ENT - Mirror Universe novel: Age of the Empress)