The de Havilland Canada C-7 Caribou was one of the few cases of a foreign contractor desiging an aircraft exclusively for a United States requirement. When it was introduced, the Caribou was the largest fixed-wing aircraft in service with the US Army and considerably larger than the earlier Beaver and Otter single engine utility aircraft which the Army also obtained from its northern neighbor. Yet despite its size, the C-7 was remarkable for its extreme ruggedness and its STOL capability which was designed for it to take off from short and unprepared strips of 1,000 feet (in practice, the Caribou could take off in even less than that!). Other than that, the C-7 featured a high-wing design with a slab-sided fuselage and a rear-end loading door which was optimized for airdropping of equippment. It was used to great success during the Vietnam War, operating from places where C-123s or C-130s could not land. Eventually, all fixed-wing aircraft were taken over by the USAF while other foreign users included a total of over 20 different countries.

The DHC-4 prototype first flew on 30 July 1958 and was ordered for US Army evaluation as the YAC-1. Production units began with the AC-1 which was later redesignated CV-2A after 1962. A nose radome and strengthened fuselage was added in the DHC-4A (AC-1A or CV-2B). Upon delivery to the USAF, Caribous were redesignated C-7A (CV-2A) and C-7B (-2B) while the very small number of units operated by the RCAF were designated CC-108.