The Curtiss P-40 Warhawk was an American single-engined, single-seat, all-metal fighter and ground-attack aircraft that first flew in 1938. The P-40 design was a modification of the previous Curtiss P-36 Hawk which reduced development time and enabled a rapid entry into production and operational service. The Warhawk was used by most Allied powers during World War II, and remained in frontline service until the end of the war. It was the third most-produced American fighter, after the P-51 and P-47. By November 1944, when production of the P-40 ceased, all 13,738 had been built at Curtiss-Wright Corporations main production facilities at Buffalo, New York. Warhawk was the name the United States Army Air Corps adopted for all models, making it the official name in the United States for all P-40s.