4. William H. Harrison, 68 years, 23 days at Start of presidency
William H. Harrison (February 9, 1773 – April 4, 1841) was an American military officer and politician who served as the ninth president of the USA in 1841. He died of typhoid or paratyphoid fever 31 days into his term (the shortest tenure), becoming the first president to die in office.
3. Ronald Reagan, 69 years, 349 days at Start of presidency
Ronald Reagan (February 6, 1911 – June 5, 2004) was an American politician who served as the 40th president of the USA from 1981 to 1989. Prior to his presidency, he was a Hollywood actor and union leader before serving as the 33rd governor of California from 1967 to 1975.
2. Donald Trump, 70 years, 220 days at Start of presidency
Donald Trump (born June 14, 1946) was the 45th president of the United States. Before entering politics, he was a businessman and television personality. Trump entered the 2016 presidential race as a Republican and defeated sixteen opponents in the primaries. Trump was elected president in a surprise victory over Democratic nominee Hillary Clinton. He became the oldest and wealthiest person ever to assume the presidency, the first without prior military or government service, and the fifth to have won the election despite having lost the popular vote.
Trump lost the 2020 presidential election to Joe Biden, but refused to admit defeat. He made unfounded allegations of electoral fraud, pressured government officials, launched a series of sixty unsuccessful legal challenges in an attempt to reverse the results, and ordered his government not to cooperate in the presidential transition. During the confirmation of the results by Congress on January 6, 2021, Trump urged his supporters to march on the Capitol, which they then stormed and searched in an attempt to force Congress to evacuate.
1. Joe Biden, 78 years, 61 days at Start of presidency
Joseph Robinette “Joe” Biden, Jr. (born November 20, 1942 in Scranton, Pennsylvania) is an American Democratic Party politician and the 46th President of the United States. From 1973 to 2009 he was a member of the United States Senate as a representative of the state of Delaware. From 2009 to 2017, he was the 47th US Vice President under President Barack Obama.
In the 2020 presidential election in the United States, he and his vice-presidential candidate Kamala Harris won against incumbent President Donald Trump, but his victory was not certain until November 7, 2020, four days after the election, when he won the majority of the electorate had gathered. The result was officially confirmed in Congress on January 7, 2021, after the votes of the electorate who confirmed Joe Biden’s election victory at the Electoral College on December 14, 2020, were counted. His inauguration was on January 20, 2021. Biden was the oldest president at 78 years and 61 days at the Start of his presidency.