Curtiss Model 75 was developted as a private venture and was scrutinized by the US Army in May 1935, but not ordered. The craft was re-examined by the Army in April 1936 when it lost a major production order to the Seversky P-35. As a concilation, Curtiss received a contract for three service-test Y1P-36s. In July 1937 a production order was placed for 210 P-36A airframes, the Army's largest fighter contract since World War I. The last 31 aircraft was completed as P-36C with engine- and armament improvements. With America's involvement in World War II on 7 December 1941, the P-36s were already considered obsolete, but circumstances compelled limited use in the opening stage of hostilities with Japan, but they were very soon relegated for use in a training role. Source - Info and Profiles: Fighters of the United States Air Force Published by Temple Press/Aerospace Books.