This map has been accorded two-fold importance in the development of the westward expansion. First, as a major contribution to geographical and cartographical knowledge and secondly, as a historic documentation of Fremont's third expedition. The map is a remarkable graphic depiction of this expedition and is considered one of the most important 19th century American maps. It covers all of the western territories from the 105th Meridian. Among the most interesting features is the appearance of the term Golden Gate at the entrance to Bay of San Francisco, the markings of the El Dorado or California Gold Fields, a hypothetical east-west mountain range near the 42nd parallel and a notation identifying the location of Mormon settlements for the first time. Wheat illustrates the map and devotes eight pages to its description. Having been court-marshaled and dismissed from the Army in 1847, Fremont was not asked to publish the details of this last expedition by the Corps of Topographical Engineers as would normally be required. Instead, the Geographical Memoir comprised his report, published nonetheless by the Congress under the powerful Senator Thomas Hart Benton, Fremont's father-in-law. The memoir is also knows as Misc. Doc. No. 148, 30th Congress, 1st Session. This is the large, and increasingly rare, map included in that report.

References: Wheat (TMW) #559; Goss (NA) #177; Schwartz & Ehrenberg plt. 171

Condition: B

Folding, as issued. A little light fold toning and a few fold intersection splits, a few closed marginal tears and one from binding trim just entering map, still a very fine example of this large map.