Mr John Daniels was actually Jasper Newton "Jack" Daniel. I should know, I live about 7 miles from the main entrance by the road, a lot less as the Crow Flies. On a damp day with a gentle breeze blowing out of the South West, I can often step out in my yard & smell the Mash a Working.
Legend has always had it that Jack learned the trade & got the formula from a minister, either Presbyterian or Luthern, I forget which offhand.
It has recently come to light that the honors truly belong to a slave by the mane of Nathan "Nearest" Green. Some of his descendants are still employed at the Distillery.
You can read all about it or watch a video here;https://www.nearestgreen.com/