Westward Expansion By terraaa. Jul 4, 1803 Louisiana Purchase The Louisiana Purchase was the acquisition of the Louisiana territory by the United States from France in 1803. Dec 24, 1814 Consequences for Native Americans Mar 15, 1818 First Seminole War Andrew Jackson invades Florida, burning and massacring Native Americans and Blacks. Feb 22, 1819 Spanish Cession May 28, 1830 Indian Removal Act Apr 21, 1836 Texas Rebellion