First Transcontinental Railroad

The railroad was built by two companies: the Central Pacific Railroad, starting from Sacramento, California, and the Union Pacific Railroad, starting from Omaha, Nebraska. The Pacific Railroad Acts of 1862 and 1864 provided land grants and government bonds, but also created a fierce race: each company was paid per mile of track, so both pushed to lay as much as possible.

The Central Pacific faced the Sierra Nevada, where crews—largely Chinese immigrants, who eventually made up about 80% of the workforce—blasted 15 tunnels through granite using black powder and nitroglycerin. The Union Pacific, staffed by Irish immigrants and Civil War veterans, laid track across the Great Plains, often at a rate of over a mile a day. The two lines met at Promontory Summit, Utah, on May 10, 1869, where the famous golden spike was driven.²

The railroad dramatically accelerated westward expansion, enabling the transport of goods, people, and mail in about seven days instead of months by wagon or ship. It spurred the growth of towns along its route, facilitated the cattle and mining industries, and made possible the rapid settlement of the Great Plains and the West.³

It also had profound negative consequences: the near-extermination of the American bison, which was hunted to feed rail crews, and the displacement and marginalization of Native American tribes whose lands were crossed. The railroad also contributed to the standardization of time zones in 1883, as train schedules required consistent timekeeping across regions.⁴

The construction was a marvel of 19th-century engineering, requiring the solution of problems like crossing the Sierra Nevada and the Great Salt Lake. The Central Pacific's use of Chinese labor was a key innovation: they were paid less than white workers but were highly efficient, and their techniques for rock work and grading were essential. The Union Pacific's use of prefabricated track sections and a mobile construction train allowed rapid progress.⁵

Working conditions were brutal: avalanches, accidents, and disease killed hundreds of workers, with estimates ranging from several hundred to over a thousand. The Chinese workers were often given the most dangerous tasks, such as handling explosives, and faced discrimination both during and after construction.⁶

One overlooked aspect is the role of the 'Big Four'—Leland Stanford, Collis Huntington, Mark Hopkins, and Charles Crocker—who controlled the Central Pacific and became enormously wealthy through construction contracts that overcharged the government. Another is the 'Promontory Curse': the golden spike was removed after the ceremony and replaced with a regular iron spike, and the original is now at Stanford University.⁷

The railroad also had a surprising environmental legacy: it introduced invasive plant species along its tracks, and the route later became a major corridor for the transcontinental telegraph and, eventually, the Lincoln Highway. Additionally, the completion of the railroad led to the creation of the first transcontinental time zones, but also to the 'Great Race' of 1869, where the two companies laid track past each other for miles before the meeting point was negotiated.¹

Golden spike

A ceremonial 17.6-karat gold spike driven at Promontory Summit to mark the completion of the railroad.

Pacific Railroad Acts

Federal laws of 1862 and 1864 that authorized and subsidized the construction of the transcontinental railroad.

Big Four

The four principal investors of the Central Pacific Railroad: Stanford, Huntington, Hopkins, and Crocker.