With the Civil War looming, construction of the Pacific railroad is being held up in Kansas, sabotaged by Confederate sympathizers. The government dispatches an Army engineer, John Nelson (Sterling Hayden, most well known as Capt. McCluskey in "The Godfather"), to oversee construction. He initially rubs the wrong way, both his proud boss (Barton MacLane) & his boss's feisty daughter (Eve Miller).
