The first trains began to run in America in the 1830s along the East Coast. By the 1840s, the nation's railway networks extended throughout the East, South, and Midwest, and the idea of building a railroad across the nation to the Pacific gained momentum. The annexation of the California territory following the Mexican-American War, the discovery of gold in the region in 1848, and statehood for California in 1850 further spurred the interest to unite the country as thousands of immigrants and miners sought their fortune in the West.
During the 1850s, Congress sponsored numerous survey parties to investigate possible routes for a transcontinental railroad. No particular route became a clear favorite as political groups were split over whether the route should be a northern or southern one. Theodore Judah, a civil engineer who helped build the first railroad in California, promoted a route along the 41st parallel, running through Nebraska, Wyoming, Utah, Nevada, and California. He was so obsessed with the idea of a transcontinental railroad that he became known as "Crazy Judah." Although Judah's plan had merit, detractors noted the formidable obstacles along his proposed route, the most serious of which was the Sierra Nevada mountain range. A rail line built along this route would require tunneling through granite mountains and crossing deep ravines, an engineering feat yet to be attempted in the