South Sulphur is on Farm Road 512 eight miles northeast of Greenville in north central Hunt County. Settlement of the community began in the mid-1850s, when farmers, attracted by the rich soils of the Blackland Prairie, moved into the area. The town was named for the South Sulphur River and received a post office in 1857. Community development was interrupted by the Civil War, and the post office closed in 1867. Eight years later, however, it reopened, as the population increased, and South Sulphur became a community center for area farmers. The number of residents remained under 100, however, and the post office was again closed in 1904. South Sulphur had seventy to eighty residents between 1900 and the 1930s, and the Great Depression reduced the population to twenty-five by 1945. Over the next fifty years the community slowly grew, to a population of sixty in the late 1980s through 2000.