This map is the culmination of fifty years of government exploration in the West and is one of the foundation maps for the western United States. Starting with Lewis and Clark, there were numerous official and unofficial surveys and explorations, all adding to the pool of knowledge presented here. While large sections are still labeled "unexplored territory," Emory combined these fragments with the information gathered during his surveys into a reasonably correct cartographic picture of the West. This map shows the large, transitional territories of Nebraska, Kansas, New Mexico, Utah, Oregon, Washington and Minnesota. It was drawn by Thomas Jekyll under the supervision of Lt. Nathaniel Michler of the Topographical Engineers. Lt. Michler worked with his counterpart representing Mexico, Captain Francisco Jimenez, to survey between Nogales and Yuma including the area south of Arivaca.

References: Wheat (TMW) #916.

Condition: B+

Issued folded, now pressed. Very light toning on two folds. Old owner's label on verso and red pencil outline to New Mexico Territory and along the Rio Grande.