Presidential longevity took a slide in the 19th century. The 10 presidents after Madison lived, on average, to be 70. Averages have bounced around since, pulled down by the assassinations of two presidents in their 40s and two in their 50s.

The more recent presidents have lived longest. The last three to die were all nonagenarians: Bush at 94, Gerald Ford and Ronald Reagan at 93. These men—along with Jimmy Carter, who is alive and well at 94 and will reach Bush’s age March 21—are the four longest-living presidents in history. Interestingly, all four ran against at least one of the other three. The only other two presidents to reach 90 were John Adams and Herbert Hoover. Both failed to win re-election.