Couple of more to add to the list.

Gordon Lightfoot song called "The Patriot Dream" from his Don Quixote album.

Phil Ochs wrote a number including "Draft Dodger Rag" and "Talking Vietnam".

Song called "Saigon Bride" by Joan Baez from her album "Joan", 1967.

John Denver did a couple. Think "Jimmy Newman" is one of the best. Another is "Readjustment Blues" from the Aerie album, 1971.

More obscure is a song call "(Still Waiting at) The Wall" written by Tim Murphy. Have this on a tape of Irish music by Pat Garvey. Beautiful song.