Shot on 42 days over the course of three years. Hundreds of people worked on the project during that time.
After the film's premiere in July 2007, the late executive producer George Hickenlooper urged director Grega to submit the film to Sundance Film Festival. Hickenlooper and Grega carefully examined the film premiere version and decided to shoot more footage and re-shoot some of the key scenes in Missouri. Eventually Sundance still passed on it.
Director Chris Grega says that the actual shoot was a cold and miserable experience and a constant race against time and circumstances. One of his favorite memories of the production was in Effingham, Illinois where after a great day of shooting with the German reenactors and vehicles the whole cast and crew went out for a steak dinner.
During the grueling shoot in the early 2007, Grega suspected having a heart attack and was driven to the hospital. After a series of tests it turned out that he was just stressed. Grip Elizabeth Bruning was injured when a smoke bomb exploded in her hand, causing a burn and setting part of the hill on fire.
Since some of the scenes were light on extras, director Grega ended up playing a dead American and a dead German during one of the scenes.