Your interest, from your request, I would guess is centered on music appearing on 'race' recordings and on the 'hillbilly' recordings of the same period. These songs, as near as we can gather from late 19th c. references, seem to have originated as recognizable genres about that time. Both have strong ties to camp meeting-gospel and to the gin mill of the working man, opposing but complimentary sources. Additions from prison and work camp (logging and turpentine, railroad, agriculture, etc.) and from old ballads remembered are found in both.
Not a simple topic!