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.
Ulysses S. Grant as commanding general, 1865–1869
Grant won the election by 300,000 votes out of 5,716,082 votes cast, receiving an electoral college landslide, of 214 votes to Seymour's 80. Grant, at the age of 46 became the youngest president on record. His election was a triumph of principles that included sound money, efficient government, and the restoration of Southern reconstructed states. When he assumed the presidency, Grant had never before held elected office and, at the age of 46, was the youngest person yet elected president. Grant was the first president to be elected after the nation had outlawed slavery and granted citizenship to former slaves. Implementation of these new rights was slow to come; in the 1868 election, the black vote counted in only 16 of the 37 states, nearly all in the South. Grant lost Louisiana and Georgia primarily due to Ku Klux Klan violence against African American voters.