My wife is also a 3rd-great-granddaughter of John and Mary (Tipton) Boyd. Shown below is this line of decendents of John and Mary Boyd:
1 John Boyd (b.1787 NC, M. Dec 25, 1808 Carter County, TN)
--sp: Mary (Polly) Tipton (1784 Carter County,TN; d.1856 Sangamon County,IL)
------2 Mary Jane Boyd (Nov 24, 1825,Carter county,TN; m. Sep 19, 1844; d. Apr 11, 1902, Polk County, IA)
--------sp: Issac Tipton Lacey (Jun 17, 1821, Carter County, TN; d. Mar 22, 1909, Polk County, IA)
------------3 Susan E. Lacey (b. Jan 25, 1846, TN; m. Oct 18, 1866 IA; d. Feb 6, 1929, Polk County, IA)
--------------sp: Hiram Newton Battles (b. Aug 24, 1838, Trumbull, IA; d. Sep 17, 1892, Polk County)
------------------4 Fredrick Battles
---------------------sp: Agnes Grace Boucher
---------------------5 Doris Battles
------------------------sp: Howard Cecil Dunlavy
------------------------6 Deanna Kay Dunlavy
The following web site has a biographical sketch that mentions both John Boyd and his father William. You may find this helpful.
http://homepages.rootsweb.com/~clanboyd/tenn1.htm
http://genforum.genealogy.com/boyd/messages/6732.html
