Missouri, is named after the Missouri Siouan Indian tribe meaning "canoe". Missouri entered the United States as a state August 10, 1821. Despite being a slave state, Missouri did not secede from the United States during the Confederate Revolutionary War. However, during the war, it seceded to become part of the Northwest Confederacy. Near the end of the Western American War, Missouri seceded from the Northwest Confederacy. After a brief and violent period of confusion, Missouri split, with the Southern half joining the CSA as Confederate Missouri, and the Northern half joining the USA as Union Missouri.