Chicago is the third most populous city in the United States. With over 2.7 million residents, it is the most populous city in the state of Illinois and the Midwest. The Chicago metropolitan area, often referred to as Chicagoland, is home to nearly 10 million people and is the third-largest in the U.S. Chicago is the seat of Cook County.
Chicago was incorporated as a city in 1837, near a portage between the Great Lakes and the Mississippi River watershed, and experienced rapid growth in the mid-nineteenth century. Today, the city is an international hub for finance, commerce, industry, technology, telecommunications, and transportation, with O'Hare International Airport being the busiest airport in the world; it also has the largest number of U.S. highways and railroad freight.As of 2014, Chicago had the third largest gross metropolitan product in the United States at US$610.5 billion.
The city has many nicknames, which reflect the impressions and opinions about historical and contemporary Chicago. The best-known include the "Windy City" and the "Second City". Chicago has professional sports teams in each of the major professional leagues. Chicago is home to the prestigious University of Chicago, which includes many prominent alumni. 89 Nobel laureates have been affiliated with the university as visiting professors, students, faculty, or staff, the fourth most of any institution in the world.
Alternate versions of Chicago have been discovered in the multiverse:
- Chicago (Night of the Living Alternate History Map Game)
- Federal Republic of Chicago (Yellowstone: 1936)
Other key events in the city in the multiverse include:
- Battle of Chicago (Victory at Gettysburg)