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. Later that day, Johnson took the presidential oath of office aboard Air Force One. Johnson was convinced of the need to make an immediate transition of power after the assassination to provide stability to a grieving nation. He and the Secret Service, not knowing whether the assassin acted alone or as part of a broader conspiracy, felt compelled to rapidly return to Washington, D.C.. Johnson's rush to return to Washington was greeted by some with assertions that he was in too much haste to assume power. Johnson signed the Civil Rights Act of 1964 into law on July 2. Terry's report prompted Congress to pass the Cigarette Labeling and Advertising Act in July 1965, requiring cigarette manufacturers to place a warning label on the side of cigarette packs stating: 'Caution: Cigarette Smoking May Be Hazardous to Your Health.'