Jimmy Carter once thought he was nearing death. The longest-living former U.S. president just turned 95.

Jimmy Carter, the 39th president of the United States, has celebrated multiple record-breaking milestones in recent years: The 40th anniversary of his inauguration was in 2017; he joined George H.W. Bush as the only other president to reach the age of 94; and in March, at 94 years and 172 days, he became the longest-living former president in U.S. history.

Now, Carter is 95. To help the low-key former chief executive celebrate his birthday on Tuesday, the Carter Center is inviting people all over the world to send him birthday messages.

Carter has reached yet another milestone despite thinking he was on the verge of death just a few years earlier, after doctors discovered that cancer had spread to his brain.

Born on Oct. 1, 1924, in Plains, Ga., the typically cheery and humble former Navy lieutenant has had a life of service. Before taking office as president, he served as a state senator in Georgia and as governor.

His presidency — remembered for the Camp David accords, the Iran hostage crisis and the creation of the Departments of Energy and Education — flamed out during the election of 1980, when Ronald Reagan defeated him.

After leaving the White House in 1981, Carter, then 56, and his wife, Rosalynn, returned to their hometown in southern Georgia. Yet another distinction: Carter has been a former American president longer than anyone.