Gouverneur K. Warren
Map of the Territory of the United States…to Accompany the Reports of the Expeditions for a Railroad Route
United States War Department
This map by Lt. Gouverneur K. Warren of the Army’s Topographical Engineers shows territory examined as part of the Pacific Railroad Surveys. Warren compiled all information received from the survey parties into this single map which provided an overview of the four main routes examined between the Midwest and the Pacific.