Does your Andrew have a brother Robert DOTSON and a half brother named John Thomas LOGAN? If so, I may have some additional information for you. John T's mother Julia supposedly married 3 times. She had a daughter and John T by Mr. LOGAN (perhaps John) who was killed about 1850 in an Indian attach on the journey west. She had sons Andy and Robert by Mr. Dotson. Don't know where the other husband fits in, who he was, or if he even existed.
What is your source for information about the family of Andrew Tyson DOTSON? No time right now, but if you respond, I'll be glad to share what I've discovered.