The "first" version of "De Blue Tail Fly," 1846, is given in thread 40458, 24 Oct. 01. Note that the refrain "Jim Crack Corn" is not in this original:
Blue Tail Fly

In the same thread, "Jim Crack Corn," treated as a separate song, is given by Masato Sakurai, along with "Blue Tailed Fly," from Christy's Nigga Songster, c. 1850. The minstrel shows revised and reworked material constantly, but these versions are the earliest in print. The two songs were soon combined in some performances.

No way are they Negro spirituals. They are minstrel songs. Some speculate that the origin could be African-American, in part based on Negro secular songs, but so far, no evidence has been found.

The thread linked here, and others linked at the head of this thread, contain much more information (as well as some nonsense) about these songs.