Sarahville de Viesca, located at the falls of the Brazos on the west bank of the river four miles southwest of the site of present Marlin, was founded in 1834 by Sterling C. Robertson and named for his mother, Mrs. Sarah (Maclin) Robertson, and for Agustín de Viesca. It was the site of the land office for Robertson's colony. Fort Viesca, later known as Fort Milam, was built at Sarahville de Viesca for the protection of the settlers. After reaching a population of approximately 200, the community was abandoned in 1836 as a result of Indian hostilities and the approach of the Mexican army.
Sarahville de Viesca should not be confused with Viesca, Coahuila, Mexico, nor with a townsite to be named Viesca that was proposed by Stephen F. Austin in 1830 to be located on the east bank of the Lavaca River at the mouth of the Navidad.
The name of the municipality of Viesca was presumably applied to the Robertson colony area from the founding of Sarahville de Viesca until December 26, 1835, when the name was changed to Municipality of Milam. Texas historians have frequently confused the Municipality of Viesca with Viesca Precinct, which lay below the Old San Antonio Road in Austin's colony.