In 1962, United States Navy began preliminary work on VAX (Heavier-than-air, Attack, Experimental), a replacement for the A-4 Skyhawk with greater range and payload. A particular emphasis was placed on accurate delivery of weapons to reduce the cost per target. The requirements were finalized in 1963 and in 1964 the Navy announced the VAL (Heavier-than-air, Attack, Light) competition. Since the upcoming General Dynamics F-111B was supposed to fulfill the advanced strike role, the NAL was intended to be only an interim solution. To minimize costs, all proposals had to be based on existing designs. Vought, Douglas Aircraft, Grumman, and North American Aviation responded. The Vought proposal was selected as the winner on 11 February 1964, and on 19 March the company received a contract for the initial batch of aircraft, designated A-7. In 1965 the aircraft received the popular name Corsair II, after Vought's highly successful F4U Corsair of World War Two.

The A-7 enjoyed the fastest and most trouble-free development period of any American combat aircraft since the second world war. The YA-7A made its first flight on 27 September 1965, and began to enter Navy squadron service late in 1966. The first Navy A-7 squadrons reached operation status on 1 February 1967, and began combat operations over Vietnam in December of that year.