When Joseph R. Biden Jr. takes the oath of workplace on Wednesday, he would be the oldest particular person ever sworn in as president. Mr. Biden turned 78 in November.

Throughout the marketing campaign, Mr. Biden addressed his age head-on in interviews and introduced himself as a “transition candidate” who would assist nurture new Democratic expertise.

“It’s a reliable query to ask about my age,” Mr. Biden said on “The View,” including, “Hopefully, I can show not solely with age has come knowledge and expertise that may make issues so much higher.”

Mr. Biden leveraged his age as a power within the election and campaigned on two key messages, in line with one historic knowledgeable.

“The primary one: ‘I’m not him,’ that means Trump,” Jeffrey A. Engel, director of the Middle for Presidential Historical past at Southern Methodist College in Dallas, mentioned on Wednesday. “The second was, ‘I’m an grownup and I’ll deliver again normalcy and I’ll deliver again a way of decency and show maturity.’”

Here’s a take a look at a few of the oldest and youngest presidents to take workplace.

Till Mr. Biden is sworn in on Wednesday, President Trump holds the document for the nation’s oldest chief government. He was 70 in January 2017, when he turned the forty fifth president.

Earlier than him, President Ronald Reagan was the oldest president. He was 69 in 1981 when he was inaugurated for his first time period.

In a debate with Walter Mondale throughout his 1984 re-election marketing campaign, Mr. Reagan made mild of the problem of age.

“I need you to know that additionally I can’t make age a difficulty of this marketing campaign,” he said. “I’m not going to take advantage of for political functions my opponent’s youth and inexperience.”

Mr. Reagan was 77 after his second time period, the oldest president to depart workplace.

Greater than a century earlier than him, William Henry Harrison held the excellence of being the oldest president on the time, when he was inaugurated in 1841 at age 68. Mr. Harrison, who had caught a chilly that developed into pneumonia, died after 32 days in office. He turned the primary president to die in workplace and thus far, has served the shortest tenure in U.S. presidential historical past.

At 96, Jimmy Carter is the oldest residing former president.

Many individuals might imagine John F. Kennedy, who was inaugurated in 1961 at age 43, was the youngest president. However that distinction belongs to Theodore Roosevelt, who was 42 in September 1901, when he assumed the presidency after the assassination of William McKinley.

“I don’t assume most Individuals have ever seen a transferring image of Teddy Roosevelt and never, definitely, whereas he was president,” Professor Engel mentioned, explaining why individuals could consider Kennedy because the youngest American president. “They don’t have a psychological picture of a younger man within the White Home at that age, whereas John F. Kennedy was all in regards to the picture and transferring photographs.”

Different youthful presidents embrace Ulysses S. Grant, who was 46 when he took workplace in 1869; Invoice Clinton, who was additionally 46 at his first inauguration, in 1993; and Barack Obama, who was 47 at his first inauguration in 2009. Three of the 5 youngest presidents have been Democrats; Roosevelt and Grant have been Republicans.

As dictated by the United States Constitution, the president should be a natural-born citizen of the USA, not less than 35 years outdated and a resident of 14 years.

The {qualifications} for president haven’t modified since George Washington first took workplace at 57 in 1789, in line with the Library of Congress. He was sworn in on the balcony of Federal Hall on Wall Street in New York Metropolis, then the capital of the USA.

A 2011 JAMA article on presidential growing old, which didn’t embrace Mr. Trump, noticed that the common age of a U.S. president at inauguration was 55.1 years.

An analogous rating discovered that on common, presidents are sworn in at 55, in line with potus.com, a mission created by Bob Summers in 1996 as a part of a graduate faculty mission on the College of Michigan College of Info.

“The general public that turn out to be president normally must construct a physique of labor to show to voters what they stand for and the way they may get issues executed,” Mr. Summers mentioned.

“That normally precludes a lot youthful presidents,” he added. “And with the shorter life expectations within the early days of the U.S., there weren’t as many individuals who would run as older candidates.”

There have been two father-and-son units of presidents, and each have been comparable in age once they every first took workplace.

John Adams was 61 when he turned the second president, in 1797. His son John Quincy Adams was sworn in because the sixth president at 57 in 1825.

George Bush was 64 at his inauguration in 1989. Twelve years later, he watched his eldest son, George W. Bush, inaugurated at 54.

Alain Delaquérière contributed analysis.