The film is about the construction of the American First Transcontinental Railroad. It depicts Irish, Italian, and Chinese immigrants, as well as African Americans, as the men who did the backbreaking work that made this feat possible. The primary villain is an unscruplous businessman who masquerades as a renegade Commanche. It culminates with the scene of driving of the golden spike at Promontory Summit on May 10, 1869. There is a note in the title before this scene that the two original locomotives from the 1869 event are used in the film, although this is false - both engines (Union Pacific No. 119 and Jupiter (locomotive)) were scrapped before 1910. Main stars were George O'Brien (Actor) and Madge Bellamy.