FWIW, Ron Byrnside wrote an entire book on "Music in Eighteenth Century Georgia" (U. Ga. Press, 1997), in which he could only assume that the early settlers sang ballads like "Barbara Allen." The contemporary references just weren't there.

This sort of thing makes me wonder. Could it be, Steve, that most of the American popularity of Child ballads came from some sort of latterly unnoticed "broadside/songster revival" from around 1830?

Just thinking out loud.