Illinois is the most populous and demographically diverse midwestern state in the nation. An important transportation hub as well; the Port of Chicago connects the Great Lakes to the Mississippi River. Approximately 66% of the population resides primarily within the city of Chicago and the surrounding metropolitan areas. Chicago is the largest city in the state and the third most populous city in the United States. Other major urban areas include the Illinois portion of Greater St. Louis, the Illinois portion of the Quad Cities area, the Champaign-Urbana metro area and the Bloomington-Normal area.