Interactive Map By aislinnwash Mar 17, 1783 United States Mar 17, 1803 Louisiana Purchase Mar 17, 1810 West Florida Annexation Begins Mar 17, 1813 West Florida Annexation Ends Mar 17, 1818 Red River Cession Mar 17, 1819 East Florida Mar 17, 1842 Webster Ashburton Treaty Mar 17, 1845 Texas Annexation Mar 17, 1846 Oregon Territory Mar 17, 1848 Mexican Cession Mar 17, 1853 Gadsden Purchase