Question: What branch of armed forces, was the subject of "Battle Hymn of Lt. Calley" a member of?
Sentence (from "William Calley"): William Laws Calley Jr. (born June 8, 1943) is a former United States Army officer convicted by court-martial of murdering 22 unarmed South Vietnamese civilians in the My Lai Massacre on March 16, 1968, during the Vietnam War.
Relevant evidence: Yes