It was to be an all-weather, carrier-based stealth bomber replacement for the Grumman A-6 Intruder in the United States Navy and Marine Corps.

[3][6] The A-12 was promoted as a possible replacement for the Air Force's General Dynamics F-111 Aardvark, and for the United Kingdom's Panavia Tornado fighter-bombers.

[9] Beginning in early 1990 General Dynamics and McDonnell Douglas revealed delays and projected cost increases.

[6] Technical difficulties with the complexity of the radar system to be used also caused costs to increase; by one estimate the A-12 was to consume up to 70% of the Navy's budget for aircraft.

[6] After delays, its critical design review was successfully completed in October 1990 and the maiden flight was rescheduled to early 1992.

In December 1990 Secretary of Defense Dick Cheney told the Navy to justify the program and deliver reasons why it should not be canceled.

The response given by the Navy and the contractors failed to persuade the Secretary of Defense, as he canceled the program in the following month, on 7 January 1991, for breach of contract.

The Super Hornet uses the General Electric F414 turbofan engine, which is a modified variant of the upgraded F404 version developed for the A-12.

[16] The full-size A-12 mockup was revealed to the public at the Naval Air Station Joint Reserve Base Fort Worth in June 1996.

[20]) The manner in which the program was canceled led to years of litigation between the contractors and the Department of Defense over breach of contract (General Dynamics Corp. v. United States).

[21][22] In September 2010, the U.S. Supreme Court said it would hear the two companies' arguments, that the government canceled the project improperly and that the use of the state secrets privilege by the U.S. prevented them from mounting an effective defense.