Geological Map of the Route Explored by Lieut. A.W. Whipple…

A rough sketch of America’s geography along the 35th Parallel.

This colorful map of the western United States was issued as part of the monumental efforts undertaken by Congress to determine the most effective route for the nation’s first Transcontinental Railroad. Six different surveys were launched to ascertain the landscape of America’s newly acquired western territories, and the results were ultimately published in 1854 as part of the Explorations and Surveys to ascertain the most practicable and economical route for a Railroad from the Mississippi River to the Pacific Ocean.

The image reflects data obtained by the survey led by Amiel Weekes Whipple along the 35th parallel, between approximately Memphis, TN and Los Angeles, CA. A finely detailed image notes the party’s route and labels various landmarks, geographic features, and settlements. Splashes of color, applied by hand, denote various geologic formations (Jules Marcou was the official expedition geologist).