L.B.J. became President upon the assassination of President Kennedy in 1963. The federal investigation concluded that J.F.K. was assassinated by gunshot from an upstairs Dallas, Texas building window. This happened while J.F.K. was riding in the Presidential Limousine (with the top removed) in a motorcade of cars passing through the downtown Dallas area. J.F.K.'s wife, Jacqueline was in the car by his side, when J.F.K. was shot. (L.B.J. was in another car, only two cars behind Kennedy's, but was not hurt.)
The assassination was caught on grainy film by an amateur photographer ("the Zapruder Film") standing alongside the parade route. The person believed to have been the assassin (Lee Harvey Oswald) was later caught by police, but Oswald was then killed by another man (Jack Ruby) a few days later when the Dallas Police were transferring the murder suspect through a group of news photographers. There have been multiple theories debated by legal experts and average citizens over the motive, and who was responsible for J.F.K.'s killing. (Learn more about the JFK Assassination at:
https://cnn.it/3tjNsr8)
Upon J.F.K.'s death in Dallas, Texas, Lyndon B. Johnson ("L.B.J.") took the Oath of Office aboard 'Air Force One' (the President's Airplane), and was officially sworn in to the Office of the President of the United States. J.F.K.'s coffin was loaded onto the same plane to return to Washington, D.C. for the public funeral procession and burial that occurred a few days later. J.F.K.'s wife, Jacqueline Kennedy, stood next to L.B.J. as he recited his oath.