A contemporary of the Hawker Hurricane and Messerschmitt Bf 109, it was one of the first of a new generation of combat aircraft—a sleek monoplane design with a retractable undercarriage making extensive use of metal in its construction.

The distinctive landing gear, which rotated 90° to fold the main wheels flat into the thin trailing portion of the wing, resting atop the lower ends of the maingear struts when retracted, was a Boeing-patented design for which Curtiss had to pay royalties.

On 27 May 1935, the prototype was flown to Wright Field, Ohio, to compete in the USAAC fly-off for a new single-seat fighter, but the contest was delayed because the Seversky entry crashed on its way there.

Curtiss took advantage of the delay to replace the unreliable engine with a Wright XR-1820-39 Cyclone producing 950 hp (710 kW) and to rework the fuselage, adding the distinctive scalloped rear windows to improve visibility.

The USAAC was concerned about political turmoil in Europe, and about Seversky's ability to deliver P-35s in a timely manner, and therefore wanted a backup fighter.

The Y1P-36 (Model 75E) was powered by a 900 hp Pratt & Whitney R-1830-13 Twin Wasp engine, and the scalloped rear canopy was further enlarged.

[citation needed] Argentina bought a number of the simplified, fixed landing gear Hawk 75Os, (intended for rough-field operations and ease of maintenance) and purchased a manufacturing license for the type; 30 were built and delivered by Curtiss, and 20 produced locally.

The Hawk was found to have lighter controls than the Spitfire at speeds over 300 mph (480 km/h), especially in diving attacks, and was easier to maneuver in a dogfight (thanks to the less sensitive elevator).

[4] Although the Hawk was considered obsolete, a number saw service with the RAF and Royal Indian Air Force (RIAF) in India and Burma.

In April 1941, the government of British India ordered 48 Cyclone-powered Mohawk IVz (Hawk 75A) for the RIAF, to be built by Hindustan Aircraft.

[8] The prototype of the Hawk 75H—a simplified version with fixed landing gear, like the 75O—was eventually sold to the Chinese Nationalist government who presented it to Claire L. Chennault for personal use.

On 11 January 1939, five Hawk 75Ms of the veteran CAF 25th Fighter Squadron led by commander Liu Yijun (劉依鈞) were flown to the new wartime capital of Chongqing in preparations for defense duties there; Liu Yijun and his four specially-trained Hawk 75 pilots all died in the crash of transport aircraft in the return flight.

[10] The Hawk 75A-5 was built under license in China, but production was later moved to India, and these aircraft were absorbed into the RAF as the Mohawk IV.

While sufficient during the early phase of the Continuation War, the increasing speeds and armor of Soviet aircraft soon showed this armament was not powerful enough.

The negotiating process ended up being very drawn-out because the cost of the Curtiss fighters was double that of the French Morane-Saulnier M.S.406 and Bloch MB.150, and the delivery schedule was deemed too slow.

Since the USAAC was unhappy with the rate of domestic deliveries and believed that export aircraft would slow things down even more, it actively opposed the sale.

Eventually, it took direct intervention from U.S. President Franklin Roosevelt to give the French test pilot Michel Detroyat a chance to fly the Y1P-36.

Detroyat's enthusiasm, problems with the MB.150, and the pressure of continuing German rearmament finally forced France to purchase 100 aircraft and 173 engines.

A few months later, this aircraft was part of "Groupe de Chasse II/5 La Fayette" (heir of the Escadrille Lafayette that fought in France during World War I), wearing the famous Sioux Head on its fuselage side.

After the first few examples, aircraft were delivered in pieces and assembled in France by the Société Nationale de Constructions Aéronautiques du Centre.

Officially designated as the Curtiss H75-C1 (the "Hawk" name was not used in France), the aircraft were powered by Pratt & Whitney R-1830-SC-G engines of 900 hp and had instruments calibrated for the metric system, a seat for French dorsal parachutes, a French-style throttle which operated in reverse from U.S. and British aircraft (full throttle was to the rear rather than to the front) and armament of four (later models had six with two firing through the prop and four in the wings) 7.5 mm FN-Browning machine guns, aimed with a French-supplied Baille-Lemaire gun sight.

[17] On 20 September, Sergeant André-Armand Legrand, pilot of the H75A-1 n°1 in the Groupe de Chasse II/5 La Fayette was credited of the first Allied air victory of World War II on the Western front with shooting down a Messerschmitt Bf 109E of the Luftwaffe 3/JG 53, over Überherrn.

Most of this batch (a total of 30) were delivered as advanced trainers to "Little Norway" near Toronto, Ontario, Canada, a Norwegian training base established by the London-based government-in-exile.

Portugal was officially neutral during World War II, although the Allies were allowed to use or establish ports and airfields on various Portuguese territories.

On 28 January 1941, the Royal Thai Air Force (RTAF) dispatched nine Ki-30 Nagoyas, escorted by three Hawk 75s, to bomb Pailin and Sisophon in French Indochina.

The aircraft's service history was marred by numerous teething problems with the engine exhaust, skin buckling over landing gear, and weak points in the airframe, severely restricting the performance envelope.

This saved considerable time over the traditional shipping method of having the fighters first disassembled, crated and then loaded by crane in the hold of a freighter, then unloaded and reassembled in Hawaii.

Five of the 39 P-36A Hawks at Pearl Harbor, delivered previously by the USS Enterprise, were able to take off during the attack and were credited with shooting down two Japanese Mitsubishi A6M2 Zeros for the loss of one P-36, thereby scoring U.S. aerial victories that were among the first of the Second World War.