How old was Lyndon B. Johnson when he assumed the role of President of the United States?

Lyndon B. Johnson assumed the role of President of the United States at the age of 55. This occurred on November 22, 1963, following the assassination of President John F. Kennedy in Dallas, Texas. As the Vice President at the time, Johnson was next in line to assume the presidency. Taking the oath of office aboard Air Force One, he became the 36th President of the United States and served in this capacity until 1969.