There were several people who purchased land on both sides of the Coosa River. I have not been able to trace my lineage to the Coats/Coates. I am related to the Tidmore and Caddel/l lines
The Caddel's had an island that was in the Coosa River. It is now under water after the Weise(sp) Damn was built.
They were all pioneers and came together to AL. Most were from SC & some from NC.
The Northeast Alabama Genealogical Society has a great deal of information and are very helpful in assisting you.