San Augustine County, TX is situated along Texas-Louisiana border river near Nacogdoches and its estimated 2019 census data population stood at 8,153 making it the 314th most populous county located hereabouts. Its county seat is San Augustine but other cities include Broaddus & Shelbyville with San Augustine itself equates out to San Augustine’s biggest town aside from cited county seat. This area had been created out of parts of Nacogdoches & Sabine Counties back in 1837 when local residents petitioned for new administrative boundaries - posthumously named after Spanish-colonial mission El santuario de Nuestra Señora de la Candelaria found nearby by Alonso Ávalos back late-16th century onwards.