Title: List of presidents of the United States by age
Content:  F. Kennedy was the youngest president at the end of his tenure, and his lifespan was the shortest of any president. At age 50, Theodore Roosevelt was the youngest person to become a former president. The oldest president at the end of his tenure was Ronald Reagan at 77; this distinction will eventually devolve upon Joe Biden, who was older when he took office than Reagan was when he left office. The president born after the greatest number of his successors is John F. Kennedy. He was born after four of his successors: Lyndon B. Johnson (8 years, 9 months, 7 days); Ronald Reagan (6 years, 3 months, 24 days); 
Title: Gerontocracy
Content:  Wilbur Ross, have been septuagenarians or older. In the 2020 United States presidential election, the Democratic Party nominated former Vice President Joe Biden against Trump. Either Trump or Biden would have been the oldest President in American history, with Biden ultimately prevailing. Biden was 78 when he was sworn in on 20 January 2021, making him the oldest person to be inaugurated president of the United States. The Biden administration's cabinet appointments have also reflected these gerontocratic tendencies. For example, Janet Yellen, Biden's Treasury Secretary, is 74. The Democratic Speaker of the House Nancy Pelosi, and the Republican Senate Minority Leader Mitch McConnell, are also both the oldest holders of their offices in American history. Representative Don Young and Senators Diane Feinstein and Chuck Grassley are the oldest members of congress at 87 years old. This observation has been connected to broader themes of American decline.
Title: List of presidents of the United States by age
Content:  The median age at inauguration of incoming U.S. presidents is 55 years. The specific years and days median is 55 years and 355 days, which falls midway between how old Grover Cleveland was in 1893 and Richard Nixon was in 1969. The youngest person to assume the presidency was Theodore Roosevelt, who, at the age of 42, succeeded to the office after the assassination of William McKinley. The youngest to become president by election was John F. Kennedy, who was inaugurated at age 43. The oldest person to assume the presidency was Joe Biden, who took the presidential oath of office two months after turning 78. Assassinated at age 46, 
Title: List of presidents of the United States by age
Content:  Polk had the shortest retirement of any president, dying barely three months after leaving office at age 53 (the youngest president to die of natural causes). Jimmy Carter's retirement, now 41 years, is the longest in American presidential history. At age 97, Jimmy Carter is also the oldest living president as well as the nation's longest-lived president. The youngest living president is Barack Obama, age 60. Altogether, six U.S. presidents have lived into their 90s. The first to do so, John Adams, was the longest-lived president for nearly two centuries, from 1803 until Ronald Reagan surpassed his lifespan, on October 11, 2001. The six presidents, arranged by lifespan, are:
Title: Electoral history of Ronald Reagan
Content:   This is the electoral history of Ronald Reagan. Reagan, a Republican, served as the 40th president of the United States (1981–89) and earlier as the 33rd governor of California (1967–75). At of age at the time of his first inauguration, Reagan was the oldest person to assume the presidency in the nation's history, until Donald Trump was inaugurated in 2017 at the age of. In 1984, Reagan won re-election at the age of, and was the oldest person to win a US presidential election until Joe Biden won the 2020 United States presidential election at the age of. Having been elected twice to 
Title: List of fictional United States presidencies of historical figures (K–L)
Content: In the short story "Fighting Bob" by Kristine Kathryn Rusch contained in the anthology Alternate Presidents edited by Mike Resnick, Robert La Follette won the 1924 election. He was the Progressive Party candidate, defeating the Republican incumbent Calvin Coolidge and their Democratic opponent John W. Davis. He entered office as the 31st President on March 4, 1925. However, his term in office proved to be short-lived as he died on June 18, 1925 (as he did in real life). After William Henry Harrison, who died after one month in office on April 4, 1841, he was the second shortest-serving president in US history. He was succeeded by his vice president Burton K. Wheeler, who became the 32nd President. Given that La Follette was 69 years old in 1924, he was the oldest man ever to be elected to the presidency. 
Title: 2016 in the United States
Content:  The 2016 presidential election is held. Donald Trump is elected as the 45th President of the United States and Mike Pence is elected the 48th Vice President, with Trump becoming the oldest man elected president at the age of 70 as well as the first president in history to take the office without any prior political or military experience. The win is considered one of the most shocking upsets in U.S. history, with most news outlets and experts considering a Trump victory unlikely. The result is also highly controversial due to Hillary Clinton's popular vote lead of nearly 3 million votes over Trump, 
Title: Dwight D. Eisenhower
Content:  to 89, marking the first Republican return to the White House in 20 years. He also brought a Republican majority in the House, by eight votes, and in the Senate, evenly divided with Vice President Nixon providing Republicans the majority. Eisenhower was the last president born in the 19th century, and he was the oldest president-elect at age 62 since James Buchanan in 1856. He was the third commanding general of the Army to serve as president, after George Washington and Ulysses S. Grant, and the last to have not held political office prior to being president until Donald Trump entered office in January 2017.
Title: 1980 United States presidential election
Content:  Survey research and post-election polling indicated that the landslide result had been more a repudiation of Carter than an embrace of Reagan and his conservatism. However, the public was aware that Reagan would move the nation in a more conservative direction, and were, apparently, willing to give it a chance to avoid four more years of Carter. At 69 years old, Ronald Reagan was the oldest non-incumbent presidential candidate to win a presidential election. Thirty-six years later in 2016 this record was surpassed by Donald Trump at 70 years old. It was then surpassed again by Joe Biden who was elected at 77 years old in 2020.
Title: 2024 United States presidential election
Content:  Democrat Joe Biden is the incumbent president, elected in 2020, and has stated he intends to run for re-election in 2024, which was later confirmed by Press Secretary Jen Psaki in November 2021, although no official statements have been released as of yet. He is the oldest person to assume the office, at age 78, and would be 82 at the end of his first term and 86 at the end of his second term, if re-elected. During late 2021, as President Biden was suffering from low approval ratings in the polls, there was speculation that he would not seek re-election. In the event of this occurring, Vice President Kamala Harris and Secretary of Transportation Pete Buttigieg were considered likely candidates for the Democratic presidential nomination, having both run for president in 2020. Also, if he chooses not to seek re-election, he woud be the first president since Lyndon B. Johnson to do so.

Question: who was the oldest man elected president of usa?
Answer: Ronald Reagan.
Donald Trump.