Development started in September 1942 in response to United States Army Air Forces requirement for a fighter possessing an extremely high rate of climb, using the most powerful liquid-cooled engine then available, the Allison V-3420.

The design concept was to use the outer wing panels from the North American P-51 Mustang, the tail assembly from the Douglas A-24 (SBD), and the undercarriage from the Vought F4U Corsair in a general layout much as in the Bell P-39 Airacobra with the engine located amidships with the contra-rotating propellers driven through extension shafts.

At the time, General Motors was busy in several projects towards the war effort, including the mass production of several different aircraft types, among them the Grumman TBF Avenger.

Redesigns were introduced into the long-range XP-75s including a modified tail assembly, new "bubble" canopy, and a V-3420-23 engine that corrected most of the deficiencies by the time the first P-75A Eagles entered flight testing in September 1944.

As the twin-engine Lockheed P-38 Lightning and North American P-51 Mustang demonstrated excellent long-range capabilities, the production run of the P-75A Eagle was subsequently terminated on 6 October 1944.