Who worked on the Union Pacific Railroad?

The building of the Union Pacific Railroad was a massive engineering project that required a regular supply of labor. As the work was temporary and situated in a distant location, it was difficult to attract skilled workers, so it became necessary to hire immigrant workers to make up the shortfall.
As with large-scale industrial and engineering projects in Great Britain, it was unskilled Irish workers who formed the bulk of the Union Pacific workforce. Many Civil War veterans also worked on the project, their military expertise coming in handy as the railroad made its way deep into Plains Indian territory. Workmen lived in what came to be known as "Hell on wheels" towns. These were temporary settlements, hastily constructed to provide shelter for those working on the railroads. As well as being places to sleep and eat, the "Hell on wheels" towns provided a wide range of amenities for the railroad workers, including saloons, hardware stores, and dentists' offices.