Which ethnic groups were primarily involved in building the Transcontinental Railroad?

The Transcontinental Railroad, completed in 1869, was primarily built by immigrant laborers, with a significant number coming from China and Ireland. Chinese workers were brought in particularly for the Central Pacific Railroad, which faced challenging terrain in the Sierra Nevada mountains. They became a crucial workforce known for their resilience and skill in tackling these difficult conditions.

Meanwhile, the Irish laborers primarily worked on the Union Pacific Railroad, which laid tracks westward from Omaha, Nebraska. The Irish were already an established immigrant group in the United States at the time, and they contributed significantly to the railroad’s construction in a variety of roles, including both manual labor and skilled positions.

Together, the Chinese and Irish workers formed a vital part of the workforce that constructed the railroad, enabling the nation to connect the Atlantic and Pacific coasts. This achievement was monumental in terms of transportation and trade, greatly impacting the country's economic development and the movement of people.