Hello, Evelyn...My ggggrandmother was the sister of your Mordecai Doughty. She was Rhoda Doughty/Doty who married Andrew Caddell in 1818 and came to Texas about 1834-35. They had 11 kids (9 boys and 2 girls). The first seven were born in Tuscaloosa County and the last four were born in Texas.
Several years ago (1986 & 1991) my Mom self-published 2 books that were based on her maternal line with a strong emphasis on the Caddell clan. She also included many of the related families, one of which was the Doughty family. Her work was pre-computer, so it was all done by personal visits to reference facilities, US mail, and telephone. She did a good job for an amateur. From her books, I have Joseph Sr. and his children and Jeremiah and his children. I don't know if I can add anything to those generations for you but I hope you can help me.
Using Find a Grave I ran across two of Moredcai's children...John Beal and Rebecca. My question here is, do you have a complete list of their siblings? I have discovered that children can often lead to, not only direct ancestors, but to cousins, etc. With Find a Grave, I have been able to fill some gaps that are inevitable in any family history. The internet has sped up research greatly, hasn't it?
I would appreciate any help you can give me and, of course, I would be glad to share what I have. Hope to hear from you soon.