"Johnny Has Gone for a Soldier" dates back a hundred years before the Revolutionary War, to the time of the Irish Wild Geese. There's a bit about it in "Folk Songs of North America."

From what I can gather, it was used in the Revolutionary War, the War of Independence, and the American Civil War. I think the more American versions of the song might be under the title of "Buttermilk Hill," as sung by the Weavers, for example. It's been a busy little song.