Alpha was on Preston Road (now State Highway 289) and Alpha Road four miles west of Richardson at a site now inside Dallas, in northern Dallas County. It was originally a freedmen's community that developed out of Farmers Branch and was on the principal route of transportation between Farmers Branch and Garland. A post office operated in Alpha from 1893 until 1904. E. C. Bramlett opened the first general store in 1895, and by 1933 the community had two businesses. The population was 111 in 1904 but decreased to fifty in 1933, where it remained in 1987, the last year it was listed as a community.