This was the critical map of the Mexican boundary survey. Initial work had broken down over a Mexican demand that Mexico be given the port of San Diego and the determination of the length of a league. It provides interesting detail in the vicinity of San Diego and, along with its companion map of the Vicinity of the Gila River by Whipple (see previous lot) anchors the border determination. This map is full of interesting information and is visually very attractive with calligraphy title and large compass rose. The map gives the marine league as 5564 meters - the standard today. Surveyed by Andrew B. Gray, John B. Weller, Commissioner.

References: Wheat (TWM) 616.

Condition: A

Issued folding, now backed with archival tissue.