Chicago refers to the city of Chicago, and to the Chicago metropolitan area, colloquially called Chicagoland. Chicago is the largest city in the state of Illinois, the largest in the Midwest, and, with a population of nearly three million people, it is the third-most populous city in the United States. The Chicago metropolitan area has a population of over 9.4 million in Illinois, Wisconsin and Indiana, making it also the third largest metropolitan area in the United States. [1] Chicago is located along the southwestern shore of Lake Michigan and is a major center of transportation, industry, politics, culture, finance, medicine and higher education. Chicago's monikers include the "Windy City," "Chi-Town," "Chi-City," the "Second City," and the "City of the Big Shoulders" (from Carl Sandburg's poem Chicago).