I did locate Nathaniel Ferguson and George Ferguson on the Free Negreos of Essex County, Virginia 1810-1843. This register includes 339 names alphabetized by last and first names I also located Nathaniel Ferguson marriage to Lucy Johnson May 18, 1830 in Essex County Virginia in a Index of Marriages in Essex County Virginia. There is also of book entiled Blacks in Essex County Virginia which includes local history from late 1700's to 1990's