Fredericksburg is the seat of Gillespie County, in the U.S. state of Texas. As of the 2010 Census, the city had a population of 10,530.Fredericksburg was founded in 1846 and named after Prince Frederick of Prussia. Old-time German residents often referred to Fredericksburg as Fritztown, a nickname that is still used in some businesses. The town is also notable as the home of Texas German, a dialect spoken by the first generations of German settlers who initially refused to learn English. Fredericksburg shares many cultural characteristics with New Braunfels, which had been established by Prince Carl of Solms-Braunfels the previous year. Fredericksburg is the birthplace of Fleet Admiral Chester Nimitz. It is the sister city of Montabaur, Germany. On October 14, 1970, the Fredericksburg Historic District was added to the National Register of Historic Places in Texas.