Now I find that Gillam Bannon Grayson and Henry Whitter made the first ever recording of "Tom Dooley" in 1929! Shortly after the civil war, Grayson's uncle had been involved in the capture of suspected murderer Tom Dula. However, I can't confirm that this is the same song.

The book of the Warner Collection gives some more background. Frank Proffitt's grandmother knew both Tom Dula and Laura Foster, and the song that came down in Frank's family is the one that went around the world. Frank Warner used the song in every lecture and programme from 1939 to 1959, telling the story of Tom and of Frank Proffitt. Frank Warner taught it to Alan Lomax who included it (minus the third verse) in Folk Song U.S.A. in 1947. Frank Warner recorded it in 1952, giving credit to Frank Profitt in the jacket notes. In 1958 The Kingston Trio took the Folk Song U.S.A. version and recorded it for Capitol Records, both on an album and as a single that sold more than three million copies.