Map of Routes for a Pacific Railroad — Compiled to Accompany the Report of the Hon. Jefferson Davis, Sec. of War, in Office of P. R. R. Surveys, 1855

Cartographer: Lt. Gouverneur K. Warren, Topographical Engineers (compiler and draughtsman); lithographed by Danks & Foster, New York

Year: 1855

Warren assembles the results of all 1853–55 War Department railroad surveys onto one national sheet, letting viewers compare proposed northern, central, and southern transcontinental alignments at a glance. Heavy black lines trace reconnaissance routes from the Mississippi to the Pacific, including Stevens’s 47th-parallel line, Beckwith’s Great Salt Lake corridor, Gunnison’s central traverse, and Parke’s Gila River path. Lighter hachures render mountain relief, while rivers and few settlements underscore the vast unsettled interior the road would cross. Longitude and latitude grids aid in assessing grades and distances between rival passes. A note explains the map as a “hurried compilation” pending publication of a larger-scale atlas, yet it became the go-to reference for lawmakers debating a Pacific railway in the mid-1850s.