The Allegheny County Fair began in 1846 as a plowing competition on William Martin's farm in Manchester Borough. Community support grew for an annual fair, and the first official Allegheny County Fair was held in 1849 at the Market Square House in Allegheny City, now part of the City of Pittsburgh. After outgrowing many locations, it settled in South Park in 1933, where it officially became known as the Allegheny County Fair and Western Pennsylvania Exposition. The fair gave farmers a place to compete friendly with neighbors and learn how to improve their farm programs, and its organizers took pride in providing entertainment without charging a fee. It was suspended from 1942 until 1946 during World War II, and after the war new exhibits included a farm machinery display, an industrial exposition, and a scientific progress exhibition, reflecting a broader movement toward science and technology.