Peggy Seeger sang this quite often at the Singers' Club in London (King's Cross) circa 1968-72, and I just assumed it was American (once I'd established that it was not a Ewan McColl song, which had been my first assumption!). When I heard a Clancys' recording, I took it for granted that they'd got it from Seeger, it was so similar. But maybe it was the other way round, and the recording came first. Can anyone date the recording?