Survey for a Pacific Railroad near the 35th Parallel, 1853-54

Popular opinion in the US in agreed by the mid-1850s held that private interests should build and operate any transcontinental railroad, with the federal government supplying generous land grants, loans, and military support. The expenses were apparently so staggering, and the financial returns so meager, that only one such route could be supported. In 1853 Congress authorized the scientific survey of all practical routes between the Mississippi Valley and the nation’s Pacific ports, hoping that a leading candidate would emerge after objective investigation.

The five Pacific Railroad Surveys (1853-55) were among the most ambitious and expensive federal projects undertaken before the Civil War. The surveying parties included surveyors and topographers, of course, but also scientists and artists, who recorded observations of the soils, climate, geology, botany, zoology, ethnography, and landscape. Taken together they were the first comprehensive assessment of the entire territory of the newly acquired territories now known as the American West. The compiled observations of the surveys, published in the twelve-volume Reports of Explorations and Surveys to Ascertain the Most Practicable and Economical Route for a Railroad from the Mississippi River to the Pacific Ocean are a landmark in the history of American science, and laid the foundation for still larger surveys of the West that followed the Civil War.

The two maps and geological profile reproduced here were prepared by the party led by Lieut. Amiel Weeks Whipple that surveyed a possible route near the 35th Parallel of northern latitude, in 1853. The two large maps (Nos. 1 and 2) show the suggested route and the main topographical features of the surrounding country. The solid line running east-west across the two sheets delineates the suggested route, while the dashed lines identify alternates. No single railroad that was built followed the entirety of any one of Whipple’s suggested routes, though in New Mexico, Arizona, and California, the route surveyed roughly parallels the Atchison, Topeka, and Santa Fe Railroad mainline. Lighter lines mark the trails of reconnoitering parties and of existing wagon roads. Watercourses, wells, springs, trails, routes of previous explorations, and Indian settlements are also noted. Several inset maps provide greater detail of key points along the suggested route, such as the Pecos River crossing in eastern New Mexico and Campbell’s Pass in western New Mexico. The thoroughness of the map, which supports rich comparative reading with more recent maps, might obscure the expedition’s main purpose, which was to identify a feasible railroad route.

The third map is a cross-section of the main geological formations underlying the route prepared Jules Marcou, geologist to Whipple’s expedition, gives some indication both of the scientific ambitions of the Pacific Railroad Surveys and of their practical orientation. These were among the first attempts to grasp the geological complexities of the West, a matter of great interest to anyone interested in developing its mineral and agricultural potential. Though the profile greatly exaggerates the relative heights of the mountains and valleys, we gain as well some sense of the difficulties the terrain posed to railroad construction.