To learn more, we recommend these books:

• Maps of Texas and the Southwest 1513-1900, James C, Martin,
  Texas State Historical Assn., 1999
• Atlas of Columbus and the Great Discoveries, Kenneth Nebenzahl,
  Rand McNally 1990
• La Independencia de Mexico Atlas Historico
• The Atlas of North American Exploration, William Goetzmann & Glyndwr Williams,
  Prentice Hall, 1992
• Mapping of the American Southwest, Dennis Reinhartz & Charlles C. Colley
  Texas A & M Press, 1987
• The Island of California, A History of the Myth, Dora Beale Pok,
  Bison, Books, 1995
• Mapping the West, Paul E. Cohen,
  Rizzoli, 2002
• The Mapping of California as an Island, Glen McLaughlin
  California Map Society, 1995
• The Mapping of North America, John Goss,
  Wllfleet Press, 1990
• The Plains and the Rockies, Wagner-Camp,
  John Howell-Books, 1982
• La Gran Linea, Paula Rebert,
  Univ of Texas Press, 2001
• 90 Years and 525 Miles, Robert R. Humphrey,
  Univ of New Mexico Press, 1987
• How the States Got Their Shapes , Mark Stein,
  Smithsonian Books, 2008
• Line in the Sand: A History of the Western U.S.-Mexico Border, Rachel St. John,
  Princeton University Press, 2011