U.S. Interior Secretary Deb Haaland approved a new constitution for the Cherokee Nation on Wednesday, ensuring citizenship for descendants of its Freedmen, the Black people once enslaved by tribal citizens.

“The Cherokee Nation’s actions have brought this longstanding issue to a close and have importantly fulfilled their obligations to the Cherokee Freedmen,” Haaland said in a statement.

The issue of tribal citizenship for Freedmen has long been the subject of litigation for the Five Tribes, known historically as the Five Civilized Tribes: the Cherokee, Choctaw, Chickasaw, Muscogee and Seminole nations.

The Cherokee Nation is the only one of the five that has granted full citizenship to its Freedmen, who number about 8,500.

“Our present constitution has long been in effect, but acknowledgment of that document by the secretary of the interior is of tremendous significance,” said Cherokee Nation Principal Chief Chuck Hoskin. “The U.S. Department of the Interior’s affirmation of our Constitution demonstrates the federal government’s continued respect for our great nation and our ability to govern ourselves.”

In her statement, Haaland encouraged other tribes to “take similar steps to meet their moral and legal obligations to the Freedmen.”