Linda, Isaac Clark Hicks served in the 2nd Arkansas Mounted Rifles. You should be able to find him in that regiment on the Gerdes page. He was mustered into service in Co. C, 2nd Arkansas Rifles, at Camp McRae, Osage Prairie, Arkansas, on July 20, 1861, for twelve months, and was elected third lieutenant. He was slightly wounded at Wilson's Creek on August 10, 1861. He was promoted to second lieutenant on October 14, 1861. He submitted his resignation from the service at some point before October 31, 1861 (possibly due to his wound?). His resignation was accepted on February 21, 1862, and he was discharged from the service. I found his name on a list of appointments to the Prairie County Home Guard at Brownsville on May 7, 1862. He is interred in Brownsville Cemetery (1827-1872).