The Devil's Brigade actually existed; its formal military designation was the First Special Service Force (FSSF), and alternatively known as the "Black Devils". It was indeed a joint American-Canadian unit, was comprised of three regiments of two battalions each, and was envisioned for difficult, cold-weather, mountain-warfare missions. The members were known as "Forcemen". Initially earmarked for Northern Europe, the FSSF was first sent to the Pacific, then to the Italian campaign, before finishing its service in southern France in 1944. During World War II, the brigade suffered casualty rates of 39%. Upon disbandment in 1944, each nations' Forcemen were incorporated into their national armies. Veterans of the Devil's Brigade have been meeting each year since 1945, in Montana, at the former training facility depicted in the movie, although in the movie, filming took place in Utah, as a stand-in for Montana.