Richie-

You may actually be making some progress here!

I can't find Daniel Decateur Emmett's "John come Down de Holler" but did find another reference to a "Jim Along Josey" which was another rewrite of a plantation song by the White/Black-faced minstrels of the 1840's.

BUT how about this fragment from an early 19th century field worksong (also from THE MUSIC OF BLACK AMERICANS, pp. 153):

Oh, this is the day to roll and go,
Hill-up, boys, hilo;
Oh, this is the day to roll and go,
Hill-up, boys, hilo.

Again, two birds with a single stone, "hilo" and "roll and go."

Still curious about what a "josey" might be, a riding cloak doesn't seem to ring true for a field girl.

Cheerily,
Charley Noble