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.
James K. Polk
Even before his inauguration, Polk wrote to Cave Johnson, "I intend to be President of the U.S." He would gain a reputation as a hard worker, spending ten to twelve hours at his desk, and rarely leaving Washington. Polk wrote, "No President who performs his duty faithfully and conscientiously can have any leisure. I prefer to supervise the whole operations of the government myself rather than intrust the public business to subordinates, and this makes my duties very great." When he took office on March 4, 1845, Polk, at 49, became the youngest president to that point. Polk's inauguration was the first inaugural ceremony to be reported by telegraph, and first to be shown in a newspaper illustration (in "The Illustrated London News").