Petersburg was first established on September 9, 1891, as a rural post office about 5 miles northeast at the home of Capt. Zack Peters, whose wife Margaret served as postmaster. Ed M. White built the first house at the present site about 1895, and when the Peters family moved from the area in 1896, White assumed postmaster duties. In 1902 he opened Petersburg's first business, a general mercantile store. The settlement incorporated in 1927 and elected Charles Schuler as mayor. After the Fort Worth & Denver Railroad arrived in 1928, Petersburg became an agricultural marketing center for the area.