You have the correct William S. Martin family listed in your reply.The John A. Martin in this family group was according my records, obtained from Frank Moseley, born 5 May 1842 and died 5 Mar 1908. The birthdate corresponds with the 1850 census. There begins my problem.
I have discovered that your John A (1857-1914) and married to Minnie H Syringseems to be the son of Marshall Martin and Elizabeth Jane Williams living near Greensboro,Greene Co. I am related to this Martin family also.
The William F., ennumerator's error,listed in the 1850 census as a son of William S. and Susannah Martin is really William Thomas Martin whose son and grandson were presidents of Sullins College, Bristol, VA.