Between 1852 and 1854, George Washington Marion (G.W.M.) Duck (1828-1899), his wife, Evaline White Duck (1829-1891), and their children left Somerset, Kentucky, and settled southwest of San Antonio in an area eventually called Somerset. In 1854, Duck was sworn in as Bexar County Constable and then, after Atascosa County was formed from Bexar County in 1856, elected Atascosa County Tax Assessor-Collector in 1858. He held that position until 1873 when he was elected Sheriff for multiple terms. In the early 1890s, Duck lost his wife and daughters to smallpox and buried them on his Pleasanton property. Duck later donated that portion adjoining an existing cemetery that is now known as Pleasanton City Cemetery. As a dedicated public servant, G.W.M. Duck passed away on May 22, 1899, and is buried in Pleasanton City Cemetery.