Like three other Vice-Presidents before him, Lyndon Johnson succeeded to the presidency upon the assassination of the President. He became President on November 22, 1963, following the fatal shooting of President John F. Kennedy. He was subsequently elected to a full term in 1964, but chose not to run for another full term in 1968.

As President, Johnson first had to comfort a nation wracked by the untimely death of President Kennedy. He then turned his attention to the urgent domestic problems facing the nation. He was highly successful in getting Congress to approve many of the social programs Kennedy had proposed, as well as many of his own proposals. Among his most notable achievements in domestic policy involved significant improvements in civil rights.

But Johnson's skill in congressional politics was not enough to overcome the problems raised by the Vietnam War. With the nation deeply divided over that war, Johnson surprised everyone when, on March 31, 1968, he announced that he would not be a candidate for another term.