The Ottawa Tribe of Oklahoma is one of four federally recognized Native American tribes of Odawa people in the United States. Its Algonquian-speaking ancestors had migrated gradually from the Atlantic coast and Great Lakes areas, reaching what are now the states of Michigan and Ohio in the 18th century. In the late 1830s the United States removed the Ottawa to west of the Mississippi River, first to Iowa, then to Kansas in what was Indian Territory. Following the United States Civil War, in 1867 they sold their land in Kansas to move again, to purchase land in another section of Indian Territory, in what would become northeast Oklahoma. They were authorized by Congress to buy land from the Quapaw, the predominant tribe in this area.