When Donald J. Trump became the 45th president of the United States in 2017, he was the oldest, at 70 years old, to be sworn into office. But then, Joseph R. Biden Jr. upended that record when he took the oath at 78, in 2021.
Mr. Trump reclaimed the title on Monday when he became the 47th president. He is also 78, but five months and six days older than Mr. Biden was on his inauguration.
During the election, age became a key issue for Mr. Biden, who is 82. Last summer, he faced calls to withdraw from the race because of his age following a faltering debate performance.
After Mr. Biden dropped out, Vice President Kamala Harris became the Democratic nominee. Age resurfaced as an election issue as Mr. Trump competed against Ms. Harris, almost 20 years his junior at the age of 60.
Here is a look at some of the oldest and youngest presidents to take office.
Who were the oldest presidents?
Before Mr. Trump in 2017, Ronald Reagan was the oldest president. He was 69 in 1981 when he first took office. Mr. Reagan was 77 after his second term, the oldest president to leave office.
More than a century before him, William Henry Harrison held the distinction of being the oldest president; his inauguration was in 1841, at 68. Mr. Harrison, who had caught a cold that developed into pneumonia, died on his 32nd day in office.
He became the first president to die in office and served the shortest tenure to date in U.S. presidential history.
Who were the youngest presidents?
Many people may think that John F. Kennedy, whose inauguration took place in 1961, when he was 43, was the youngest president. But that distinction belongs to Theodore Roosevelt, who was 42 in September 1901, when he assumed the presidency after the assassination of William McKinley.
Other youthful presidents include Ulysses S. Grant, who was 46 when he took office in 1869; Bill Clinton, who was also 46 at his first inauguration, in 1993; and Barack Obama, who was 47 at his first inauguration in 2009.
Who were the youngest vice presidents?
Ms. Harris was 56 years old when she became the first female vice president in 2021.
Mr. Vance is the third youngest vice president to be elected.
Who was the oldest living former president?
Jimmy Carter, who became the 39th president of the United States in 1977, was the longest living former president in American history. He died in December at 100 years old.
Mr. Carter, a Democrat born on Oct. 1, 1924, sought to unite the country after the Watergate scandal but he served only one term in office. A poor economy and an international hostage crisis curtailed his chances for re-election in 1980.
