History of Williamson County

Thompson, Karen R.
Historic Round Rock, Texas.
Waco: Eakin, 2001.

Williamson County has a long (in American terms) and wonderful history.
The county was formed in 1848 from part of Milam County. It is named after
Robert McAlpin Williamson, a veteran of the Battle of Gonzales and the
Battle of San Jacinto and friends with Stephen F. Austin and William B. Travis.