A search on Fold3.com yielded a William F. Sisk, native of Surry Co., North Carolina, Private, Co. G, 54th Regiment of North Carolina Volunteers (Paid). He is listed as a resident of Wilkes County, N.C. before enlistment, with a wife and one child. He died March 4, 1864 as a POW in Kalorama Hospital, Washington D.C of Variola Discreta. Interred at 10 o'clock, March 7, 1864; location of grave not stated. Hope this helps.