During the American Revolutionary War, many Shawnee moved from the area later defined as the Northwest Territory near the Great Lakes to Cape Girardeau, Missouri; some later moved into Spanish Louisiana. These bands were later joined by other Shawnee groups from Alabama. Some relocated southward into Arkansas Territory, Spanish Texas, and French Louisiana after the 1803 Louisiana Purchase by the United States of former French-controlled lands west of the Mississippi River. Due to encroaching European-American settlement, the Shawnee in Missouri negotiated an 1825 treaty, ceding their Missouri lands for reservations in Kansas.