The discovery of silver in Nevada leads many American and Irish workers to leave the Central Pacific Railroad in the hopes of finding their fortunes. To replenish the diminished workforce, the railroad begins hiring Chinese immigrants as labor.
The Central Pacific starts recruiting large numbers of workers from China in preparation for the construction of tunnels through the Sierra Nevada Mountains. The painstaking project will require hand-drilling 12 or 13 tunnels through the rocky terrain at a rate of a few inches per day.
Chinese workers carve out the rail bed around Cape Horn by being lowered in baskets to hammer out holes in the shale and granite, then insert and ignite black powder. Many workers are killed due to accidental explosions.
Work on the Summit Tunnel (Tunnel #6) is halted when removing rubble by hand becomes too difficult. As a solution, a vertical shaft is drilled into Tunnel #6 and a 12-ton steam engine is hauled up Donner Pass and lowered into the shaft – a feat that takes six weeks to complete. Two teams of Chinese workers descend and start blasting from the inside out, while the steam engine carts out the debris.
An unrelenting winter brings 44 storms, the worst of which lasts two weeks. Avalanches and brutally cold conditions claim hundreds of lives. Many of the 6,000 Chinese immigrants on the Sierra Nevada passage work and live in a network of tunnels dug beneath 40-foot snowdrifts.
Chinese immigrants make $30/month to work 12-hour shifts, 6 days a week. Meanwhile, Caucasian workers receive higher wages and are also provided food and shelter. Chinese workers go on strike for better pay and less hours. Central Pacific cuts off food purveyors to the Chinese camp, which forces the hungry strikers back to work after a week.
The number of Chinese workers reaches a high of 12,000, comprising at least 80% of the Central Pacific workforce.
Upon its completion on May 10, 1869, in Promontory, Utah, around 11,000 Chinese immigrants work on the Transcontinental Railroad. Over the course of its construction, an estimated 1,200 Chinese workers had lost their lives from avalanches, accidents, and explosions.