Kansas City, Missouri (Wikipedia) Kansas City, Missouri (KC or KCMO) is the largest city in Missouri by population and area. As of the 2020 census, the city had a population of 508,090, making it the 37th most-populous city in the United States. It is the urban central city of the Kansas City metropolitan area, which straddles the Missouri–Kansas state line and has a population of 2,392,035. Most of the city lies within Jackson County, with portions spilling into Clay, Cass, and Platte counties. Kansas City was founded in the 1830s as a port on the Missouri River at its confluence with the Kansas River from the west. On June 1, 1850, the town of Kansas was incorporated; shortly after came the establishment of the Kansas Territory. Confusion between the two ensued, and the name Kansas City was assigned to distinguish them soon after.