Phantom’s story began in 1952 when David S. Lewis was appointed as the preliminary design manager of McDonnell Douglas (MDD). With the team he established, he started working on the new aircraft model requested by the U.S. Navy. The aircraft would be a supersonic fighter jet. MDD started the “Super Demon” project based on the existing F3H Demon model. MDD’s rivals the Grumman XF9F-9 and the Vought XF8U-1 Crusader were already meeting the supersonic fighter requirements. In response, they started to work on the more advanced YAH-1 project in 1954. The planned design criteria were a single-seat fighter/bomber that could operate in any weather conditions (all-weather). The project was launched with these needs, but on May 29, 1955, new requirements were sent to the company by the Navy. Everything had changed suddenly. Now, the Navy wanted a tandem-seat fighter jet that could fly CAP (Combat Air Patrol) missions at 300 miles for 2 hours with the capability to detect and engage hostile aircraft at extended ranges. 

The YAH-1 project was later revised. A second crewman was added to operate the radar, the internally mounted cannon was removed, the fuselage was modified to carry four semi-active homing missiles, and the General Electric J79-GE-8 engine was selected to power the aircraft. The J79 was also used on the McDonnell Douglas F-101 Voodoo aircraft, and as in Voodoo, the engines sat low in the fuselage to maximize internal fuel capacity and ingested air through fixed geometry intakes. With all these changes, the first XF4H-1 prototype was finished and became ready for new trials. On July 25, 1955, the Navy ordered two XF4H-1 test aircraft and five YF4H-1 pre-production examples. The first test aircraft made its maiden flight on May 27, 1958, with test pilot Robert C. Little at the controls. The plane was officially named Phantom II on July 3, 1959, at the 20th anniversary of the factory to honor FH-1 Phantom, the first jet aircraft produced by McDonnell Douglas. The F4H-1 first entered service in 1960 with the U.S. Navy. In the meantime, the United States Air Force also requested a new plane. Secretary of Defense Robert McNamara wanted the same aircraft to be used in all aviation branches (Air Force, Navy, Marines) of the military. The Navy wanted the Phantom as an interceptor, while the Air Force wanted it for its fighter-bomber missions. The new Phantoms produced for the Navy are considered more successful than the Convair F-106 aircraft used by the Air Force and was selected by the USAF as well. The plane was initially designated F4H (later F-4A) by the United States Navy, while the original designation by the USAF was the F-110A Spectre (later F-4C). The F-4 designation came about in 1962 when the designation systems for all branches of the U.S. military were unified by order of U.S. Defense Secretary Robert McNamara. The first Air Force F-4C Phantom flew on May 27, 1963, exceeding Mach 2 on its maiden flight.