I did some checking in White County, Tenn because that was where Jane Duff, William's wife, was born. Also, their oldest daughter was born in Sparta, Tenn. I found a number of Duff's living there going back as far as 1815. I believe that william's family moved there when he was a child and that is where he met and married Jane. According to Census a Thomas Duff and his family were living there and I'm starting to believe they may have been Wm's parents.

Here are a couple of great sites to checking up family names in the early 1800 in Tenn

White County, Tennessee, Genealogy
http://www.tngenweb.org/white/

White County TN Genealogical-Historical Society
http://web.blomand.net/~wcolley/WCGHS.html

Hope this helps. Oh I do have a number of early Duff Photo's of Martin VanBuren Duff and his wife Betsy, One is tin plate and is not very clear.

Anita Johnson
AsaJohnson@aol.com