Cass County

Cass County is a county located in the western part of the U.S. state of Missouri and is part of the Kansas City metropolitan area. As of the 2010 census, the population was 99,478. Its county seat is Harrisonville, however the county contains a portion of Kansas City, Missouri. The county was organized in 1835 as Van Buren County, but was renamed in 1849 after U.S. Senator Lewis Cass of Michigan, who later became a presidential candidate.
The Harrisonville area was long inhabited by speakers of the Dhegihan Siouan-language family: The Osage, Quapaw, Omaha, Ponca and Kansa tribes make up this sub-group. The Kansa tribal range extended southward from the Kansas-Missouri River junction as far as the northern edge of present-day Bates County, Missouri, taking in the sites of modern Pleasant Hill, Garden City, Archie and Drexel. On their southeastern border they were neighbors of the Osage. There is no evidence that either of these tribes ever had a truly permanent settlement in the territory of Cass County.

Wikipedia