My two cents: Vaughan/Vaughn are basically one and the same.
The name William ran through the family. I also know that after the
Civil War ended, some of the family did reside in Kentucky, though
at this moment in time, I cannot tell you where.
Those folks stuck to the rule of being fruitful and multiply.
I am the gg grandchild of William Robinson Vaughn/Vaughn who was
one of seven brothers and he died flat broke in Little Rock, Arkansas in
1876, because he refused to take the oath at the end of the war.
I found this story interesting and thanks for sharing.
Linda