Tecumseh (/tɛˈkʌmsə/ te-KUM-sə; March 1768 – October 5, 1813) was a Native American leader of the Shawnee and a large tribal confederacy (known as Tecumseh's Confederacy) which opposed the United States during Tecumseh's War and became an ally of Britain in the War of 1812.Tecumseh grew up in the Ohio Country during the American Revolutionary War and the Northwest Indian War, where he was constantly exposed to warfare.