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.
Presidents of the United States on U.S. postage stamps
Ulysses S. Grant (April 27, 1822 – July 23, 1885) was the 18th President of the United States. A national hero of the American Civil War, Grant was elected president in 1868, the youngest man theretofore elected president. He was re-elected in 1872. Grant began his lifelong career as a soldier after graduating from the United States Military Academy in 1843. Fighting in the Mexican–American War, he was a close observer of the techniques of Generals Zachary Taylor and Winfield Scott. During President Johnson's term, Grant was appointed to be the Secretary of War.