There are 4 US Post Offices in Gillespie County serving a total of 24,886 residents equating to 6,222 residents per post office. It's estimated that approximately 39,721 packages are handled across the 4 county post offices annually. Gillespie County is a county located on the Edwards Plateau in the U.S. state of Texas. As of the 2010 census, its population was 24,837. The county seat is Fredericksburg. It is located in the heart of the Texas Hill Country. Gillespie is named for Robert Addison Gillespie, a soldier in the Mexican-American War. On December 15, 1847, a petition was submitted to create Gillespie County. In 1848, the legislature formed Gillespie County from Bexar and Travis Counties. While the signers were overwhelmingly German immigrants, names also on the petition were Castillo, Pena, Munos, and a handful of nonGerman Anglo names. Gillespie County comprises the Fredericksburg, TX Micropolitan Statistical Area."