The Constitution of the State of Sequoyah was adopted by the principal tribes in Indian Territory in 1905. However, the attempt of tribes to gain admission to the United States as the State of Sequoyah and thereby avoid inclusion in the proposed State of Oklahoma failed. In 1906 tribal governments in Indian Territory were abolished by Congress and tribal members were made citizens of the United States. In 1907 Indian Territory was joined with the Territory of Oklahoma and admitted into the Union as the State of Oklahoma.