born 1813 in Tennessee, died 1869 in Magoffin County, Kentucky son of Nathanial and Margaret Bennett Barnett no sources provided
If John was the son of Margaret (Bennett) Barnett, and if her husband was also the husband of Elizabeth Sutherlin (married 1810), then John must have been born before 1810.
Note: Many trees confuse him with the John Barnett who died in Casey County in May 1860 (census mortality schedule), but this John lived in Floyd County and was counted in the Floyd County census in Jul 1860.