Ada: I'm interested in whether Isaac (b. 1789) is the same Isaac Alexander who married Nancy Parsons on 20 June 1814 in Wilson Co, TN? If so, a descendant of this couple has participated in the DNA project and his results show, quite definitively, that Isaac Alexander was closely related to the the ALEXANDER grouping known as the "Seven Brothers/Two Sisters", although his parents have not been identified.If this is the same Isaac you are researching, I would very much like to put you in touch with the sponsor of this DNA participant so that you could join forces in trying to figure out his parents.
I have some information for the Isaac Alexander who was a son of David Alexander (d. ca May 1796 in Mecklenburg) with a wife named Elizabeth, but I am not certain that it is accurate: “Isaac Alexander removed to Alabama in 1794 and raised a large family of whom there are no records save the names of his children as follows:Violet Davidson, Martha Rose, Joseph McKnitt, Thomas Young, Mary Sample, Margaret Jane and Nancy Pharr. [SOURCE:Page 49.Records of a Family of the House of Alexander from 1640 to 1909 Frances Alexander Butterworth Published 1909 [s.n.] 87 pages Original from the University of Wisconsin - Madison Google Books: Digitized Apr 18, 2007 ]
The Butterworth book has some sketchy information on most of David Alexander's other children, most of whom seemed to have moved into Tennessee, so it seems odd to me that Isaac moved to Alabama, but I have not done research on this family, so I don't know enough to assess the validity of the above statement.
Let me know if you are researching the Isaac Alexander in Wilson & DeKalb Co, TN.