Located on the shore of Lake Michigan, Chicago was incorporated as a city in 1837 near a portage between the Great Lakes and the Mississippi River watershed. As the seat of Cook County, the second-most populous county in the U.S., Chicago is the center of the Chicago metropolitan area. With a population of 2,746,388 in the 2020 census, it is also the most populous city in the Midwest. state of Illinois and the third-most populous in the United States after New York City and Los Angeles. Chicago ( / ʃ ɪ ˈ k ɑː ɡ oʊ/ ⓘ shih- KAH-goh, locally also / ʃ ɪ ˈ k ɔː ɡ oʊ/ shih- KAW-goh Miami-Illinois: Shikaakwa Ojibwe: Zhigaagong) is the most populous city in the U.S.