PSS If you do not have the following, let me know and I can email the document to you. Thomas Clayton & his family were in Morgan County, Ga by 1809. I have a copy of their dismissal from Antioch Baptist Church. Reference on it indicates they were founding members. Isaac would have been around 12-13 so most likely still with parents.
If you are ever in that area, the family that purcahsed the property where the Antioch Baptist Church use to be is a great guy who loves to take people around the property and talk about the history. Plus the town is cute and has some good resturants.