Huston and his crew were attached to the U.S. Army's 143rd Regiment of the 36th Division. Unlike many other military documentaries, it was claimed Huston's cameramen filmed alongside the infantrymen as they fought their way up the hills to reach San Pietro. Houston's claim that the film was made during the battle was proven false by the research of Peter Maslowski in his 1993 book, Armed With Cameras.

The film is unflinching in its realism. One scene includes close-up views of the faces of dead soldiers as they are being loaded into body bags, a level of realism unheard of in both fictional portrayals as well as newsreel footage of the time. The United States Army delayed its release to the public.

Because it showed dead GIs wrapped in mattress covers, some officers tried to prevent soldiers in training from seeing it, for fear of damaging morale. General George Marshall came to Huston and the film's defense, stating that because of the film's gritty realism, it would make a good training film. The depiction of death would inspire soldiers to take their training more seriously.

Huston quickly became unpopular with the Army, not only for the film but also for his response to the accusation that the film was anti-war. Huston responded that if he ever made a pro-war film, he should be shot. The film was screened to U.S. troops in North Africa in 1944, where John Horne Burns described it in a letter as "almost more than any heart can stand". Huston was no longer considered a pariah; he was decorated and eventually promoted to major.