1804 Louisiana Purchase organized into Territory of Orleans (Louisiana) with remainder as "District of Louisiana". Western borders in dispute with Spain until 1819. 1805 "District of Louisiana" reorganized as Territory of Louisiana. 1805 Lower Michigan organized as Territory of Michigan from Indiana Territory. 1809 Illinois Territory organized from Indiana Territory, consisting of Wisconsin, Illinois and NorthEast Minnesota. Indiana and Upper Michigan remaining in Indiana Territory. 1810 West half of West Florida seized from Spain. 1812 Territory of Louisiana reorganized into Missouri Territory (aka The Indian Country). Western border in dispute with Spain until 1819. 1812 Territory of Orleans admitted to the Union as State of Louisiana, 18th state. Western border in dispute with Spain until 1819. 1813 East half (remainder) of West Florida seized from Spain. 1816 Indiana admitted to the Union as 19th state. Remainder of Indiana Territory (Upper Michigan) added to Illinois Territory. 1817 Mississippi admitted to the Union as 20th state. Remainder of Mississippi Territory organized into the Territory of Alabama. 1818 Illinois admitted to the Union as 21st state. Remainder of Illinois Territory (Wisc., NE Minn., Mich UP.) added to Michigan Territory. 1818 Treaty with Great Britain sets Northern border at 49 degrees North. Running from Lake of the Woods (Minn.), West to the Continental Divide. Northern tip of original Louisiana Purchase (now Missouri Terr.) ceded to Britain. Lands South of border ceded to the U.S. and added to the Missouri Territory. 1818 Joint claim with Great Britain sets "The Oregon Country" as being between 42 degrees North to 54 degrees 40 minutes North with the Eastern boundry as the Continental Divide. Note- "The Oregon Country", claimed by multiple nations (France, Spain, Russia, Great Britain and the U.S.). France relinquished claims in 1803 ?with sale of Louisiana Territory? 1819 East Florida ceded by Spain. 1819 Alabama Territory admitted to the Union as State of Alabama, 22nd state. 1819 Western borders of Louisiana and the Missouri Territory set by treaty with Spain. 1819 Arkansas Territory organized from Missouri Territory. Consists of Arkansas and majority of Oklahoma. 1819 Treaty with Spain sets the Northern border of Spanish claims at 42 degrees North. Relinquishing claims to "The Oregon Country". Lands North of the border added to "The Oregon Country". 1820 District of Maine separated from Massachusetts and admitted to the Union, 23rd state. Northern boundry still in dispute with Great Britain. 1821 Missouri admitted to the Union, 24th state. Note - Current NW corner not included until 1836. 1821 Mexico (aka New Spain) declares independance from Spain. 1822 East Florida organized as Territory of Florida.
12/1998 M.A.Leonard, Last Update-01/2002