Tribal sovereignty was addressed in the U.S. Constitution and adopted in 1788. The Commerce Clause—Article 1, Section 8, Clause 3—read that Congress had the power "to regulate Commerce with foreign Nations and ... the Indian Tribes."
Thereby, Native American tribes who signed treaties with the United States are deemed "sovereign, independent nations" by the federal government. The Chickasaw's Treaty of Hopewell, signed in 1786, formally acknowledged the Chickasaw Nation's tribal sovereignty that is still recognized today.