James Adair and Alabama Descendents

I have a fairly clear and well researched line from myself to William Issac Adair Born 1780 and married to Eleanor Moon, living in Madison County AL. I'm struggling to find William Issac's parents and grandparents. Some seem to think his grandfather is James the Indian Trader. The documentation is fuzzy at most, where Dr James Adair had a son named James Adair who had William Issac.

Anyone have some incite into this, and some decent sources. I'm finding that in places like Geni people put in what they want to hear.