The Creek War (1813-1814) was a conflict between the United States and the Creek Nation, a Native American tribe in the southeastern U.S. The war arose from tensions over land and the influence of the British and Spanish in the region. The conflict involved various factions within the Creek Nation, with some tribes supporting the U.S. and others opposing it. The war ended with the Treaty of Fort Jackson in 1814, which forced the Creek Nation to cede millions of acres of land to the U.S. This significantly reduced their territory and marked a turning point in U.S. expansion into the Southeast.