Former first lady Rosalynn Carter, the devoted wife of the nation’s 39th president and a tireless advocate for mental health care, has died.

The Carter Center confirmed that she died Sunday morning at her home in Plains, Georgia, at the age of 96.

The former first lady and former President Jimmy Carter were married for 77 years. She and the former president had four children, 11 grandchildren and 14 great grandchildren.

“Rosalynn was my equal partner in everything I ever accomplished,” Jimmy Carter said in a statement from the Carter Center. “She gave me wise guidance and encouragement when I needed it. As long as Rosalynn was in the world, I always knew somebody loved and supported me.”