Developed from the C-74 transoceanic transport which first flew shortly after the end of World War II, The Douglas C-124 Globemaster II was a significant refinement over its predecessor and became one of the backbones of the US military transport fleet during the Cold War. Nicknamed 'Old Shakey', the C-124 differed from its predecessor by having a deeper fuselage and featured large clamshell doors, a built-in loading ramp, an electric hoist, overhead cranes, and was capable of carrying tanks, artillery pieces, trucks and other heavy equipment as well as 200 fully equipped troops or a smaller number of litters. The C-124 was used extensively over Korea and Vietnam as well as performing supply missions worldwide including to remote places like Antartica and Africa. They were perhaps best known, however, for carrying Thor missiles across the Atlantic to the UK during the height of Cold War tensions in Europe. C-124s served with the USAF until replaced by C-5s in 1970 after which many were used for civil duties.

The prototype YC-124 was based on the 5th example of the C-74 but featured a deeper fuselage and strengthened langing gear. Its maiden flight took place on 27 November 19949. It entered production as the C-124A and was followed by the final C-124C with more powerful engines, weather radar in a nose radome, and other improvements some of which were retrofitted into earlier C-124As.