From NKAA, Notable Kentucky African Americans Database (main entry)
Slaves of William "Billy" Stafford
Prior to the Civil War, William Stafford was a slave owner who owned land around the Big Sandy River in Johnson County, KY. When slaves died, they were buried on the land. "The graves were located about one hundred feet down in the lower [corner] of the cemetery below the family burials."
This information comes from E. R. Hazelett, "Slave burials in Johnson County," Sandy Valley Heritage, vol. 23, issue 2 (June 2003), p. 16.