Smyth County Families and History, ed. by J. M. Presgraves, Wytheville, Virginia, 1974 contains a brief history of Co. E "Smyth Greys," 50th Virginia and a roster of the soldiers who served in the company but, oddly, not your man. There is, however, a Cpl. P. D. Cox, a Lt. Wm. H. Cox, Pvt. John L. Cox, Pvt. George Cox, Pvt. Matt Cox, and a Pvt. Thomas Cox listed.