Former President Jimmy Carter blew out three candles representing the past, present and future to celebrate his 90th birthday.

Carter and his wife, Rosalynn, thanked family, friends and staff at the Carter Center in Atlanta on Wednesday morning. They gathered in a new monarch butterfly garden and then participated in a short ceremony in a chapel on the grounds.

The 39th U.S. president joked that "it's been a good first 90 years." He said his childhood in Plains, Georgia, and marrying Rosalynn have most shaped his life.

The couple launched the international health and human rights organization after leaving the White House.

Carter is the second-oldest of the five living U.S. presidents. He was born 111 days after President George H.W. Bush, who celebrated his 90th birthday earlier this year.