The Boeing 707 served as the first U.S. presidential jet, beginning with President Dwight D. Eisenhower.
The aircraft was a modified Boeing 707-120 designated VC-137A. It entered presidential use in 1959, replacing slower propeller-driven aircraft and allowing the president to travel internationally much more quickly.
The presidential aircraft was not originally called Air Force One in every situation. The radio call sign “Air Force One” became associated with the presidential aircraft after a 1953 incident involving confusion between the president’s aircraft and a commercial aircraft using a similar call sign. The designation applies whenever the president is aboard an Air Force aircraft.
Later presidents used improved VC-137C versions of the 707, including aircraft known as SAM 26000 and SAM 27000. The 707 was eventually replaced in presidential service by specially modified Boeing 747 aircraft.