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.
Frank McCarthy (producer)
Shortly after the end of the war, President of the United States Harry Truman named McCarthy Assistant Secretary of State for Administration under United States Secretary of State James F. Byrnes. Only 33 years old at the time, McCarthy is thus the youngest Assistant Secretary of State in United States history. However, he only held the office as a placeholder, from September 1, 1945 until October 11, 1945, when he was replaced by Donald S. Russell.