I complied with your email early this morning, Otis. With some ISPs, one has to modify one's email profile to _deliberately_ specify that you'll receive mail from a specific email address. It's not really anything to worry about, but I've been burnt before when I didn't check my spam folder for too long and information from other Abernathy researchers got deleted before I even knew it'd been sent. In this case, your ISP seemed to bounce the message rather than even putting it in your spam folder. Interesting, that.
After that was done, I tried gathering a bit of source information relative to this issue. And was nonplused to find that in 1811, when you found David, David Jr, and Joseph on that Maury County TN tax list, I now find ancestry showing not one but two David Abernathys on an 1811 Madison County AL census, one David Abernathy on an 1815 Madison County AL census, _three_ David Abernathys on an 1816 Madison County census (one in the Mississippi Territory and the other two in the Alabama Territory). If some of these aren't duplicates of themselves, we sure seem to have a lot of David Abernathys running around in North Alabama and Central TN 'round about then!
Now the current problem I have is the source of those sources, if you get the drift. Once or twice before I followed a reference from that source only to find I could not locate any names that source claimed were to be found in that county/state for that specific year. I want to see actual photo-copy images of these early Alabama Census records. Problem is, I don't know where to find them. But I am beginning to be as leary regarding references from the AIS index as from certain LDS Family History Library sources.
It really does pay to verify for oneself from the earliest available original source, whenever possible!