The manual labor to build the Central Pacific's roadbed, bridges and tunnels was done primarily by many thousands of emigrant workers from China under the direction of skilled non-Chinese supervisors. The Chinese were commonly referred to at the time as 'Celestials' and China as the 'Celestial Kingdom'.

Labor-saving devices in those days consisted primarily of wheelbarrows, horse or mule pulled carts, and a few railroad pulled gondolas. The construction work involved an immense amount of manual labor.