Final answer:
The Central Pacific Company mainly employed Chinese immigrants for the construction of the Transcontinental Railroad, enduring tough and hazardous work conditions while laying railroad track.
Step-by-step explanation:
The Central Pacific Company primarily relied on Chinese immigrants as their workforce. During the construction of the Transcontinental Railroad, thousands of Chinese laborers were hired to lay rails across the challenging Sierra Nevada mountains. Despite the grueling and poorly paid work, these men persevered, driven by the desire to earn income for their families back in China. While the Union Pacific Railroad also employed various groups, including Civil War veterans and other immigrants, the Central Pacific's workforce was significantly made up of Chinese immigrant laborers, who faced some of the most difficult and hazardous conditions.