Northwest of Abilene, Rotan is at the intersection of Hwys 70 and 92, near the Double Mountain Fork of the Brazos in northwest Fisher County. A community called White Flat, named for the powdery white gypsum sand that lies near the surface of the land, had been established at the site before county organization in 1886. In 1935 the Rotan Gypsum Plant was sold to the National Gypsum Company, which began a series of expansions that eventually made the facility one of the largest gypsum plants in the country.
Residents numbered 2,788 in 1960, 2,404 in 1970, and 2,284 in 1980. The railroad, which had ceased passenger service in the 1920s, was discontinued in the late 1970s. In 1990 Rotan's economy depended on agribusiness, an oil mill, and the gypsum plant, and the community had a population of 1,913.