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.
Grover Cleveland
Cleveland entered the White House as a bachelor, and his sister Rose Cleveland joined him, to act as hostess for the first two years of his administration. Unlike the previous bachelor president James Buchanan, Cleveland did not remain a bachelor for long. In 1885 the daughter of Cleveland's friend Oscar Folsom visited him in Washington. Frances Folsom was a student at Wells College. When she returned to school, President Cleveland received her mother's permission to correspond with her, and they were soon engaged to be married. On June 2, 1886, Cleveland married Frances Folsom in the Blue Room at the White House. He was the second president to wed while in office, and has been the only president married in the White House. This marriage was unusual, since Cleveland was the executor of Oscar Folsom's estate and had supervised Frances's upbringing after her father's death; nevertheless, the public took no exception to the match. At 21 years, Frances Folsom Cleveland was the youngest First Lady in history, and the public soon warmed to her beauty and warm personality.