Largely sidelined by history, 15,000 to 20,000 Chinese workers were instrumental in the construction of the US Transcontinental Railroad in the 1860s. In 1867, 90% of the railroad labor force were Chinese since white workers were reluctant to perform back-breaking manual labor. Abused, underpaid, and forced to do the most dangerous of tasks, these long-overlooked Chinese workers built American infrastructure.