James Abourezk, who was the first Arab American U.S. senator, has died.

He was a South Dakota Democrat who grew up on the Rosebud Indian Reservation and was known for his quick wit as he advocated for populist causes.

Abourezk’s son, Charles Abourezk, said his father died at his home in Sioux Falls on Friday after going into hospice care earlier this week. Abourezk represented South Dakota for single terms in the U.S. House and U.S. Senate during the 1970s.

He was the first chair of the Senate Committee on Indian Affairs and authored the Indian Child Welfare Act. After retiring from the Senate, he founded the American-Arab Anti-Discrimination Committee.

He died on his birthday, at the age of 92.