John Wayne and William Holden lead a group of Union soldiers behind Confederate lines during the Civil War. 

Midway through the film the Union troops barricade a town in preparation for the arrival of a Confederate army train. These scenes were filmed on the western town set at MGM's Lot 3 in Culver City, which already had a depot set and stretch of track. Virginia & Truckee's #11 "Reno" leads the train. 

Troops pile out of old boxcars (likely built for the film), which are later blown up in the carnage. They even prepare to blow up the engine! Luckily the Reno survived and today is awaiting restoration in Virginia City, NV.