Kansas City, or K.C., is the largest city, and second largest metropolitan area, in the state of Missouri. It is the 37th–largest city by population in the United States and the 23rd–largest by area. It is the central city of the Kansas City metropolitan area, which straddles the Kansas–Missouri border. It was founded in the 1830s as a Missouri River port at its confluence with the Kansas River coming in from the west. Originally called Kansas after the river, this became confusing upon the establishment of Kansas Territory in 1854. The name Kansas City was assigned to distinguish the two.