General Map Collection Texas Historic Overlay Map Research & Digitzation Project\RioGrandeEntrance_1854_USCS_00114-1.TIF
U.S. Coast survey. A.D. Bache, Superintendent. Preliminary survey of the entrance to the Rio Grande, Texas. Topography by W.E. Greenwell, assistant. Hydrography by the party under the command of Lieutenant J. Wilkinson U.S.N. Asst. Scale 20,000. Cities of Bagdad and Clarksville are present. Relief shown by hachures. Includes text on soundings and tides. Prime meridian: Greenwich. Engraved by C.A. Knight & F.W. Benner.
Maps, UTRGV Digital Library, The University of Texas – Rio Grande Valley
Maps; North America--Rio Grande; Texas--Lower Rio Grande Valley; 1850-1859