History and usage
The origin of the term is difficult to ascertain. According to the recollections of veteran Phillip Leveque:
Perhaps I should explain the derivation of the term "dogface". He lived in "pup tents" and foxholes. We were treated like dogs in training. We had dog tags for identification. The basic story is that wounded soldiers in the Civil War had tags tied to them with string indicating the nature of their wounds. The tags were like those put on a pet dog or horse, but I can't imagine anybody living in a horse tent or being called a horseface. Correctly speaking, only Infantrymen are called dogfaces. Much of the time we were filthy, cold and wet as a duck-hunting dog and we were ordered around sternly and loudly like a half-trained dog.
The term gained a high profile in the USA when it was used in the 1955 Hollywood film To Hell and Back, based on the best-selling autobiography of Audie Murphy, the most decorated U.S. soldier of World War II, and starring Murphy in the lead role. The film included a song, The Dogface Soldier, originally written in 1942 by two U.S. Army infantry soldiers; it was adopted as the song of the 3rd Infantry Division, and was widely played and sung during the war.  The song eventually sold 300,000 copies. The song is still sung every morning after reveille by the soldiers of the 3rd Infantry Division while in garrison at Fort Stewart, Georgia and Hunter Army Airfield, Georgia.
The term is also mentioned in "The Caine Mutiny" by Herman Wouk: "'If they decide to survey this bucket we'll sit on the beach with the dogfaces for a year waiting our chance for a ride back. Fix the pumps and you've got your private limousine to take you home, maybe in a week. How about another look at the pumps?' The pumps were repaired in two days." In this instance it does not have the same meaning as a soldier "dogface," but a face like a sad dog.
- Alchemy For A Foxhole-A Salute to the ASTP Men http://www.89infdivww2.org/memories/levequeastp1.htm
- The Dogface Soldier http://www.dogfacesoldiers.org/info/dogface.htm
- Wouk, Herman (15 January 2013). "The Caine Mutiny: A Novel of World War II". Little, Brown – via Google Books.