Round Rockbr/Williamson County, Texasbr/30 30.905' N 97 41.397' W br/br/Text: The earliest structure in this complex is the one-story stone building, constructed about 1853. It originally housed a mercantile store and the first permanent post office for Round Rock, both operated by Thomas C. Oatts, the town's first postmaster. Built on the pioneer road from Austin to Georgetown, it was part of Round Rock's early development. The two-story home was built about 1870 and for many years was the residence of Dr. William M. Owen, a prominent local physician and businessman. Both buildings reflect the style of other area structures of the 19th century.