Sandburg: New American Songbag (1950) pp.56-57. I had assumed from the reference in the DT file that the text there was from Sandburg, but evidently this is not the case.

Interesting that Baez' comment that the song "has an Elizabethan ring" turns into someone's else's belief that she said that "the song is Jacobean in origin". Sounds and reads like a Victorian parlour ballad to me.