Theodore Dehone Judah (March 4, 1826 – November 2, 1863) was an American civil engineer who was a central figure in the original promotion, establishment, and design of the First transcontinental railroad.

As chief engineer, he performed much of the route survey work to determine the best alignment for the railroad over the Sierra Nevada, which was completed six years after his death.

[6] Judah was hired in 1854 at age 28, by Colonel Charles Lincoln Wilson, as the Chief Engineer for the Sacramento Valley Railroad in California.

Much of the Sierra Nevada where the practical routes were located was double-ridged, meaning two summits separated by a valley, Donner Pass was not and thus was more suitable for a railroad.

[20][11] Judah's youthful interest in the general subject of a Pacific Railroad developed during this period into almost an obsession, his wife observing that...

Failing to raise funds for the Central Pacific project in San Francisco, Judah succeeded in signing up five Sacramento merchants, : James Bailey, Leland Stanford, Collis P. Huntington, Mark Hopkins, and Charles Crocker.

In a report dated October 1, 1861, Judah discussed the results of the survey, the merits of the chosen Dutch Flat-Donner Pass route,[22] and the estimated costs from Sacramento to points as far as Salt Lake City.

the Theodore Judah map), 30 inches tall by 66 feet long, of the proposed alignment of the Central Pacific Railroad.

With a minimal survey crew utilizing crude instruments and only draft animals for transportation, Judah was able to lay out a remarkably accurate alignment across the most difficult natural obstacles undertaken up until that time (1861)."

J. David Rogers and Charles R. Spinks, ASCE Golden Spike 150th Anniversary History Symposium, Sacramento, CA, May 6, 2019[11] Sources