Return to Andrews Air Force Base; President Kennedys body placed in ambulance; President Johnson speaks to the nation. President Lyndon B. Johnson (at microphones) delivers remarks to the nation after taking the oath of office aboard Air Force One and arriving at Andrews Air Force Base in Maryland; First Lady Lady Bird Johnson stands next to President Johnson. Also pictured: Special Assistant to President Kennedy, Arthur M. Schlesinger, Jr.; Military Aide to President Kennedy, General Chester V. Clifton; Speaker of the House of Representatives, John W. McCormack (Massachusetts); Representative Cornelius E. Gallagher (New Jersey); Representative Carl Vinson (Georgia); Representative Albert Thomas (Texas); media liaison, Jack Valenti; Representative Carl Albert (Oklahoma); Representative Charles A. Halleck (Indiana); White House Secret Service agents, Toby Chandler, Ernie Olsson, and Rufus Youngblood. A United States Army helicopter sits in the background.