Forney is on U.S. Highway 80, the Missouri Pacific Railroad, Buffalo Creek, and Mustang Creek, twenty-three miles east of Dallas in northwestern Kaufman County. When the earliest settlers arrived and established a community in this area they found a broad expanse of fertile blackland prairie covered with grass. By 1870 several of these settlers, including John C. McKellar, who established the first general store in the settlement, were calling their town Brooklyn, reportedly because several springs flowed together to form a brook nearby. Soon after McKellar's store was opened, a saloon and a blacksmith shop began operation in Brooklyn.
The citizens applied for a post office in 1873, but it was discovered that there was a Brooklyn in Shelby County. That same year the promoters of the Texas and Pacific Railway, having failed to interest the residents of either the county seat, Kaufman, or Cedar Grove in the rail line, chose to build between these communities and through the Brooklyn settlement. In honor of the railroad and in hopes of winning federal approval for the local post office, the residents of Brooklyn renamed their community Forney, on December 29, 1873, after the Pennsylvania journalist, politician, and member of the board of directors of the T&P line, John Wien Forney, then employed as a civil engineer to direct the Texas and Pacific in the area. Forney was officially incorporated in 1884, and soon afterward a mayor-alderman form of local government was established.
The railroad and fertile soil attracted settlers to Forney after 1873, and the town grew as a farm center and residential community. The population increased slowly for the next century, to more than 3,000 residents by 1960. The surrounding land is used as ranchland and for the production of cotton, corn, grain, and onions. Although situated in a predominantly agricultural area, Forney has been a small manufacturing community since 1936. Its factories have produced such goods as cottonseed oil, ice, athletic supplies, paper products, and plastics. In 1964 Forney Reservoir was constructed on the East Fork of the Trinity River four miles north of Forney. The reservoir, impounded to provide water for Dallas, was later renamed Lake Ray Hubbard.
The population of Forney in 1980 was 2,483. The increase was partly a result of the growth of Dallas. Three local manufacturers produced plastics, recycled-paper products, and insulation products. The Forney Messenger, first published in 1881, continued to serve as the community's weekly newspaper. Forney's first public school was built in 1874. A Black school opened in 1890, and Forney Academy, a private coeducational school, was established by 1894. Just north of the town, along Highway 80, are located some fifteen warehouses that sell antiques and antique reproductions. In 1990 the population was 4,070, and in 2000 it was 5,588.