Chicago is the largest city in the state of Illinois, the largest in the Midwest and, with a population of 2.8 million people, is the third largest in the United States. Rich in history and renowned for its architecture, Chicago is classified as an alpha world city. It is the anchor of the Chicago metropolitan area, commonly called Chicagoland, which has a population of over 9.5 million people in Illinois, Wisconsin and Indiana, making it the third largest metropolitan area in the U.S. The City of Chicago is almost entirely located in Cook County, Illinois, with a small portion in DuPage County, while the metropolitan area extends over several counties.
Founded in 1833 at the site of a portage between the Great Lakes and the Mississippi River watershed, it soon became a transportation hub and the business, financial, and cultural capital of the Midwest. Since the Chicago World's Fair of 1893, it has been regarded as one of the ten most influential cities in the world.