The presidency of Lyndon Baines Johnson began on November 22, 1963, when Johnson became the 36th President of the United States upon the assassination of President John F. Kennedy, and ended on January 20, 1969. The presidency of Lyndon Baines Johnson began on November 22, 1963, when Johnson became the 36th President of the United States upon the assassination of President John F. Kennedy, and ended on January 20, 1969. He had been Vice President of the United States for 1,036 days when he succeeded to the presidency. A Democrat from Texas, he ran for and won a full four-year term in the 1964 election, winning by a landslide over Republican opponent Arizona Senator Barry Goldwater. Johnson sought not only to win passage of the bill, but also to prevent Congress from stripping the most important provisions of the bill and passing another watered-down civil rights bill, as it had done in the 1950s.