Chicago is the third largest city in the United States in terms of population, and with more than 2.8 million people, the largest city in the state of Illinois and the Midwestern United States. Located on the southwestern shores of Lake Michigan, bordering the Illinois-Indiana State Line, Chicago is the third-most densely populated major city in the U.S., and anchor to the world's 26th largest metropolitan area with about 9.6 million people across three states. The Chicago-Naperville-Joliet, IL-IN-WI MSA also grew by an estimated 470,995 people between April 1, 2000 and July 1, 2008. Except for the southwest corner of O'Hare International Airport which is in DuPage County, the city of Chicago is located in Cook County.