A year after the Louisiana Purchase was made, it was formed into an organized territory. The Louisiana Territory was anything above Arkansas, which interestingly enough doesn’t even include current day Louisiana. Meriwether Lewis and William Clark, renowned explorers of the Western U.S., both served as Governors for the territory.
On this day June 4th, in 1812, the Louisiana Territory is renamed the Missouri Territory. On April 30th Louisiana had been admitted as a state, and to avoid confusing it was simply decided that the territory would be renamed. Score for clarity.
The Territory of Missouri remained in existence until August 10, 1821. Americans poured into the Missouri Territory as treaties were continuously made with Native Americans, so the new settlers could live there in peace. During the War of 1812 the Missouri Territory’s capital St. Louis was used as army headquarters. St. Louis went on to become a commercial center of the U.S., and there was massive commerce within the Missouri Territory and Louisiana when the steamboat came about in the early 19th century.