The Indian Territory and the Indian Territories are terms that generally described an evolving land area set aside by the United States Government for the relocation of Native Americans who held aboriginal title to their land as a sovereign independent state. In general, the tribes ceded land they occupied in exchange for land grants in 1803. The concept of an Indian Territory was an outcome of the US federal government's 18th- and 19th-century policy of Indian removal. After the American Civil War (1861–1865), the policy of the US government was one of assimilation.