The aircraft started life as a project for an attack aircraft, designated XA-43. When the United States Army Air Forces issued a requirement for a jet-powered all-weather fighter in 1945, the design was reworked for that request.
The XP-87 was a large mid-wing aircraft with four engines paired in underwing pods, with a mid-mounted tailplane and tricycle undercarriage. Two crew members (pilot and radar operator) sat side by side under a single canopy. Armament was to be a nose-mounted, powered turret containing four 20 mm (0.79 in) cannon, but this was never fitted to the prototypes.
The first flight of the XF-87 Blackhawk was on 1 March 1948. Although the top speed was slower than expected, the aircraft was otherwise acceptable, and the newly formed (in September 1947) United States Air Force placed orders for 57 F-87A fighters and 30 RF-87A reconnaissance aircraft just over a month later. Since the performance problems were due to lack of power, the four Westinghouse XJ34-WE-7turbojets of the prototypes were to be replaced by two General Electric J47 jets in production models. One of the two XF-87 prototypes was to be converted to the new powerplants for test purposes.
At this point, the USAF decided that the Northrop F-89 Scorpion was a more promising aircraft. The F-87 contract was cancelled on 10 October 1948, and both prototypes were scrapped.