St. William Catholic Church is located in Round Rock, Texas near the Brushy Creeek that was part of the Chisholm Trail. To protect pioneers from Indian raids, some forts were established along Brushy Creek as early as 1635. The first community to be established in the area soon became known as Brushy. When the area attempted to get a post office, the US Postmaster General would not approve the name because it had already been assigned to another village in East Texas. In 1854 the local postmaster selected the name of Round Rock because of the well- known stone which marked a safe crossing over Brushy Creek.