Thomas Grimke Rhett was a graduate of the United States Military Academy at West Point, New York and a United States Army officer who served from July 1, 1845 to April 1, 1861. He served in the Mexican-American War in 1847–1848. Rhett was awarded a brevet appointment as captain for gallantry in the defense of Puebla, Mexico during the Siege of Puebla, October 12, 1847. After his resignation from the U.S. Army, April 1, 1861, he was appointed a brigadier general in the South Carolina Militia but did not serve in that office. He was a staff officer in the Confederate States Army in the Eastern Theater of the American Civil War from April 1861 until May 31, 1862. He first served as voluntary aide-de-camp to General Pierre G. T. Beauregard and then major from April to July, 1861. Rhett then se