As construction began on the Central Pacific Line, railroad organizers were finding it impossible to retain the thousands of workers needed to lay track. White, mostly Irish, workers would quit after building up savings to seek their fortunes in the gold fields. The Central Pacific questioned where they might find the sustained manpower needed to finish the job.
For them, the answer lay in the Chinese, who had experienced great difficulties in California after emigrating during the Gold Rush of 1849. They were barred from participating in public life, yet had to pay extra taxes. Politicians, notably head of the Central Pacific and Governor of California Leland Stanford, began running on anti-Chinese platforms.
Chinese workers were first brought to railroad work to send a message to Irish workers that they were expendable. Yet work from the Chinese gave the Central Pacific great returns on the meager $30 a month it paid each laborer and thus they eventually comprised 80 percent of the workers on the line. The Chinese would brave the hazardous conditions of tunneling and accomplish incredible feats of track laying, including one period where they put down 10 miles in 12 hours.
A more diverse group was responsible for the construction of the Union Pacific line, including Irish Civil War veterans and newly freed slaves looking for paying jobs in the more progressive West. Mormons also comprised a significant portion of the Union Pacific workforce because of a collective desire to see the railroad incorporate Utah into the rest of the nation.