There are a lot of requirements that you need to meet to become president of the United States. Even though the vast majority of presidents have been of advanced age, as they need to have a lot of experience before they can successfully run for office, someone only has to be 35 years old to be elected president of the United States. In addition, they need to have been born in the United States. Someone who was born overseas is not allowed to be president, according to the Constitution, someone also has to have lived in the United States for the past 14 years to be approved to hold office.
The youngest person to ever hold the office of President of the United States was Theodore Roosevelt. He took over at the age of 42. When William McKinley was assassinated, Theodore Roosevelt was his vice president. That meant that he immediately took office as soon as McKinley passed away. The youngest person to be elected president was John F Kennedy. He was inaugurated at the age of 43. He was also the youngest president at the end of his tenure, as he was assassinated at the age of 46. Overall, the average age at which someone becomes president is approximately 55 years of age.
The oldest person to become president of the United States is Joe Biden. Joe Biden took the oath of office approximately two months after turning 78. Assuming he survives until the end of his presidency, he will also be the oldest president to conclude his tenure as president. Prior to Joe Biden, the oldest president at the end of his tenure was Ronald Reagan. Ronald Reagan completed his tenure as president of the United States at the age of 77. He was the oldest person to do so when he left office.
After a president leaves office, they are considered retired. It is highly unusual for an ex-president to consider returning to politics and another office. James K Polk had the shortest retirement of any president in the history of the United States. He died approximately three months after he finished his tenure as president. Right now, the longest retirement of someone who has held the office of President of the United States is Jimmy Carter. He served as president of the United States from 1976 to 1980. He has been retired for close to 42 years, and he has enjoyed the longest retirement of any ex-president. There are several other presidents who are still alive. Examples include Barack Obama, Bill Clinton, and George Bush jr. It remains to be seen what many of these presidents are going to do during their retirement years, as many still hold significant influence.