Individual Details

[Birth year estimated from marriage of parents. In references, including his father's Will, Madison is always listed first; presumably the elder of the two boys.]

I believe he also married several years prior to Jacob. The following is probably his marriage:
James M. Thomas to Sarah Adams, 17 Oct 1813, Halifax Co, VA
Virginia Marriages, 1740-1850; Ancestry.com
William Adams was father of the bride.

Caswell Co NC Deeds:
DB S, p.123-4 4 Apr 1818. James M. Thomas of Halifax Co VA to Romulus M. Sanders of Caswell for $500, all claim to lot #24 in Milton where Asa Thomas Thomas died to which he is entitled being heir to Jacob Thomas brother of Asa Thomas. Wit: Henry Hooper, Monrow Epperson.

[I believe his name must have been James Madison Thomas]

Birth

Abt 1794

Father	Jacob Thomas (1767 - 1803)
Mother	Hannah Farley ( - )
Sibling	Jacob Thomas (1797 - )