Thomas was a lawyer and politician and one of the signers of the Texas Declaration of Independence. He was born in Tennessee around 1801 and came to Texas in 1835, joining a volunteer cavalry company in Nacogdoches. He participated in the Texas independence movement, and at the 1836 Convention, we was elected as the acting attorney general for the provisional government. He was later appointed acting Secretary of War. When on route to Galveston aboard the steamer Cayuga, he was mortally wounded by an accidental discharge. Sources vary on when and where he died from the wound.