He was educated principally at Cane Hill, Arkansas, and studied law at Fayetteville, in the office of W. D. Reagan.
[1] Thomason first came into prominence as a politician as presidential elector when he canvassed the state against the celebrated Thomas C. Hindman.
He was one of the delegates to the congress of the Confederate States at Montgomery, Alabama, with Robert W. Johnson, Albert Rust, William W. Watkins, and Augustus H. Garland from May 18, 1861, to February 17, 1862.
[1] Thomason was elected judge of the 15th judicial circuit in September 1890,[2] which position he held at the time of his death.
[1] He was buried at Fairview Cemetery (Van Buren, Arkansas), on July 31, 1893, with Masonic honors.