Born in Pittsylvania County, Virginia, Thomas attended local schools as a child and went on to graduate from a private academy in 1838.

Thomas read law and was admitted to the bar in 1844, commencing practice in Martinsville, Virginia.

After approval of the new state Constitution (and rejection of a proposed provision forbidding former Confederates from holding office), Thomas served in the Virginia House of Delegates in 1869, both succeeding fellow Confederate delegate and Conservative George W. Booker and being succeeded by him.

He ran against former Confederate officer and Conservative Democrat Alexander Davis, who was initially declared the victor, but Thomas contested the result and was seated.

However, Thomas served only a single term from 1874 to 1875, losing his reelection bid in 1874 to Democrat George Cabell, another lawyer and former Confederate officer active in railroad promotion.