Missouri Territory
On March 2, 1819, all of the Missouri Territory south of the parallel 36°30' north, except the Missouri Bootheel between the Mississippi River and the Saint Francis River north of the 36th parallel north, was designated the new Territory of Arkansaw. (The spelling of Arkansaw would be changed a few years later, although the proper pronunciation of the name would be debated until 1881.) The southeastern portion of the Missouri Territory was admitted to the Union as the State of Missouri on August 10, 1821.