Chicago metropolitan area

The Chicago metropolitan area, or Chicagoland, is the metropolitan area that includes the city of Chicago, Illinois, and its suburbs, spanning 14 counties in northeast Illinois, northwest Indiana, and a small portion of southeast Wisconsin. The population is about 9.5 million people and CSA population of 9.9 million people, it is the third largest metropolitan area in the United States.
The Chicago metropolitan area is one of the world's largest economies, with more than four million employees and making an annual gross regional product (GRP) of over $561 billion. The region is home to more than 400 major corporate headquarters, including 31 in the Fortune 500.