Civil War Confederate Brigadier General. An 1844 graduate of the United States Military Academy at West Point, New York, he won a brevet for gallantry in the Mexican War. After resigning from the army in 1853, he engaged in business in St. Louis and was active in the Missouri militia, holding the rank of Brigadier General in 1861. Paroled after his capture at Camp Jackson, he was not exchanged until after General Sterling Price's capture of Union officers at Lexington, Missouri. In March 1862 he was promoted to the rank of Brigadier General in the Confederate army. He served as a staff officer to General Braxton Bragg and under Major General Thomas Hindman in Arkansas at the Battle of Prairie Grove. General Frost left the army for Canada as a result of the banishment of his wife and family from their home near St. Louis. Unfortunately, he left without bothering to advise the Confederate War Department and was dropped form the rolls in 1863. After the war he returned to St. Louis, where he farmed until his death.