Westward Expansion By yeri0375 Sep 25, 1783 United States Sep 25, 1803 Louisiana Purchase Sep 25, 1810 Florida Sep 25, 1818 Red River Cession Sep 25, 1842 Webster Ashburden Treaty Sep 25, 1845 Texas Annixation Sep 25, 1846 Oregon Territory Sep 25, 1848 Mexican cession Sep 25, 1850 major city Sep 25, 1850 Salt Lake City and San Francisco Sep 25, 1853 Gadsden purchase