10. Lyndon Baines Johnson
Johnson was quickly sworn in as President on Air Force One in Dallas on November 22, 1963, just 2 hours and 8 minutes after John F. Kennedy was assassinated, amid suspicions of a conspiracy against the government. He was sworn in by U.S. District Judge Sarah T. Hughes, a family friend. In the rush, a Bible was not at hand, so Johnson took the oath of office using a Roman Catholic missal from President Kennedy’s desk. Cecil Stoughton’s iconic photograph of Johnson taking the presidential oath of office as Mrs. Kennedy looks on is the most famous photo ever taken aboard a presidential aircraft.