Rank: Second Lieutenant
Unit: 2d Dragoons
Commissioned: United States Military Academy class of 1842 and appointed from Virginia.
Campaign: Mexican American War
Died: 25 April 1846
Age at death: 27
Cause of death: Killed in action
Location of fatality: Rancho De Carricitos, Texas
Notes: 43rd in his class of 55 graduated cadets. Bvt. Second Lieut., 2d Dragoons, July 1, 1842. Served: at the Cavalry School for Practice, Carlisle, Pa., 1842, — Ft. p145 Jesup, La., 1842‑43, — Expedition to Arkansas River, 1843, — Ft. Leavenworth, (Transferred to 1st Dragoons, Mar. 6, 1843) Kan., 1843‑44, — Scouting to Pawnee Villages, 1844, — Ft. Leavenworth, (Second Lieut., 2d Dragoons, Sep. 13, 1844) Kan., 1844, — and Ft. Jesup, La., 1844‑45; in Military Occupation of Texas, 1845‑46; and in the War with Mexico, 1846, being engaged in the Skirmish of La Rosia, near Ft. Brown, Texas, where he was killed.
Notes: He was part the “Thornton Affair.” It was the justification needed for the United States to declare war on Mexico.
The conflict began due to a border dispute between the United States and Mexico, concerning the territory between the Nueces and Rio Grande rivers, which both countries claimed. After moving south into Texas, as part of Brig. Gen. Zachary Taylor’s Army of Observation, the 2d Dragoons were the first to engage in combat. On 25 April 1846, Capt. Seth Thornton and Companies C and F were attacked by a superior force of approximately 1600 Mexican Soldiers. 16 Dragoons were killed and approximately four dozen captured to include Capt. Thornton.