ATLANTA (AP) Jimmy Carter, already the longest-living U.S. president in history , will celebrate his 98th birthday Saturday with family and friends in Plains, the tiny Georgia town where he and his wife, 95-year-old Rosalynn, were born in the years between World War I and the Great Depression.

The 39th presidents latest milestone comes as The Carter Center , which the Carters established together after their one White House term, marks 40 years of promoting democracy and conflict resolution, monitoring elections, and advancing public health in the developing world.

Jason Carter, the former presidents grandson now leading the Carter Center board, described his grandfather, an outspoken Christian, as content with his life and legacy.

He is looking at his 98th birthday with faith in Gods plan for him, the younger Carter, 47, said, and thats just a beautiful blessing for all of us to know, personally, that he is at peace and happy with where he has been and where hes going.