Gainesville is a city in and the county seat of Cooke County, Texas, United States. The population was 15,538 at the 2000 census.
Founded in 1850, the city of Gainesville was established on a 40-acre tract of land donated by Mary E. Clark. City residents called their new community Liberty, which proved short-lived, as a Liberty, Texas already existed. It was suggested by one of the original settlers of Cooke County, Colonel William Fitzhugh, that the town be named after General Edmund Pendleton Gaines. Gaines, a United States General under whom Fitzhugh had served, had been sympathetic with the Texas Revolution.
The first hint of prosperity arrived with the Butterfield Stagecoach in September 1858, bringing freight, passengers, and mail. During the Civil War, the Great Hanging, a controversial trial and hanging of suspected Union loyalists, brought the new town to the attention of the state and came close to ripping the county apart. In the decade after the Civil War, Gainesville had its first period of extended growth, catalyzed by the expansion of the cattle industry in Texas. Gainesville, only seven miles from the Oklahoma border, became a supply point for cowboys driving herds north to Kansas. The merchants of Gainesville reaped considerable benefits from the passing cattle drives.