Charles St. Clair had previously served in Co. K, 14th (Powers') Arkansas Infantry. He enlisted as first corporal at Yellville, Arkansas, on August 5, 1861, for twelve months. He deserted at Camp Priceville, near Tupelo, Mississippi, on July 29, 1862, which is how he happened to wind up at Helena, where he enlisted in the 2nd Arkansas Cavalry, U.S. Volunteers, on September 10, 1862.