Alan Thompson provided a link to the Lemke, Walter J., The War-Time Letter of Albert O McCollom, Confederate Soldier, Washington County Historical Society, Fayettville, Arkansas, 1961 https://dcms.lds.org/delivery/DeliveryManagerServlet?dps_pid=IE1103022

This document indicates that Company E of Brooks Arkansas Cavalry Battlion was origionally designated as the "Davis Light Horse".