Jeff Cooper was a United States Marine, the creator of the “modern technique” of handgun shooting and an expert on the use and history of small arms. In 1976, Cooper founded the American Pistol Institute (API) in Paulden, Arizona (later the Gunsite Academy).
Cooper began teaching shotgun and rifle classes to both law enforcement and military personnel, as well as civilians and did on-site training for individuals and groups from around the world.
He sold the firm in 1992, but continued living on the Paulden ranch. He was known for his advocacy of large caliber handguns, especially the Colt 1911 and the 45 ACP cartridge.