Williamson County is named for Robert M. Williamson, pioneer leader and veteran of the Battle of San Jacinto; created from Milam County, organized March 13, 1848, and located in Central Texas just north of the state capitol in Austin. Physically, the eastern part of the county is level black land soil and the western part rolling limestone hills, all drained by the San Gabriel River and tributaries. The county has a lively history including Comanche’s, outlaws, Texas Rangers, the Chisholm Trail, cowboys, and sturdy pioneers. The Comanches arrived in the area in the eighteenth century and lived in parts of the Territory of Williamson County until as late as 1838. After they were crowded out by Anglo-American settlements who arrived in the late 1830’s, the Comanches continued to raid settlements in the county until the 1860’s. There also appear to have been small numbers of Tonkawas, Kiowa, Yojuane, Tawakoni, and Mayeye Indians living in the county at the time of the earliest Anglo settlements.
The county occupies 1,137 square miles and is divided into two regions by the Balcones Escarpment, which runs through the center from north to south along a line from Jarrell to Georgetown to Round Rock. The western half of the county is an extension of the Western Plains and is undulating hilly brush land with an average elevation of 850 feet, while the eastern region is part of the Coastal Plains and is flat to gently rolling with an average elevation of 600 feet.
Population estimates on a sampling of towns in Williamson County for January 1, 2015:
Andice (300); Bartlett (3,344, partly in Bell County); Brushy Creek (23,472); Cedar Park (67,995, part  in Travis County); Coupland (280); Florence (1,207); Georgetown (59,805), county seat; Granger (1,473); Hutto (19,904); Jarrell (1,112); Jollyville (16,959, partly in Travis County); Leander (34,811); Liberty Hill (1,077); Round Rock (117,280, part [1,362] in Travis County); Schwertner (175); Taylor (16,592); Thrall (891); Walburg (277); Weir (483). Also, part [35,697] of Austin and Thorndale has a small portion in Williamson County. (Source: Texas State Historical Association, Texas Almanac)