Barbour served as Justice of the Peace for Orange County, from 1768 until his death. From 1769 until 1776 (although the prorogued house had no quorum after June 24, 1775), Barbour represented Orange County in the Virginia House of Burgesses.[3] He was a Whig.[4] Thomas died at his son James Barbour's plantation, Barboursville on May 16, 1825.[1][2][4]