List of presidents of the United States by age
The median age upon accession to the presidency is 55 years and 3 months. This is how old Lyndon B. Johnson was at the time of his inauguration. The youngest person to assume the office was Theodore Roosevelt, who became president at the age of , following William McKinley's assassination; the oldest was Donald Trump, who was old at his inauguration. The youngest person to be elected president was John F. Kennedy, at of age on election day; the oldest was Ronald Reagan, who was old at the time of his election to a second term.
George H. W. Bush
His eldest son, George W. Bush, was inaugurated as the 43rd president of the United States on January 20, 2001, and re-elected in 2004. Through previous administrations, the elder Bush had ubiquitously been known as "George Bush" or "President Bush", but following his son's election the need to distinguish between them has made retronymic forms such as "George H. W. Bush" and "George Bush senior" and colloquialisms such as "Bush 41" and "Bush the Elder" much more common. H.W. Bush was traveling to Minnesota for a speaking engagement on the day of the September 11 attacks. George W. made multiple calls to get in contact with his father before the two men reconnected after the elder Bush had gone to a Brookfield, Wisconsin motel. Bush told biographer Jon Meacham that his son's vice president, Dick Cheney, underwent a change following the September 11 attacks: "His seeming knuckling under to the real hard-charging guys who want to fight about everything, use force to get our way in the Middle East."