Shepard Cohen joined the Army and was in the 29th Infantry. While in the service he took a test and was assigned as a U.S. liaison officer with the British Army partaking in the preparatory exercise know as "Harlequin" as a prelude for the logistical support to "Overlord." Cohen attended the British Royal Engineers Movements Control School at Longmoor, Liss, England. With the Allies, they devised mathematical formulas for logistical movement of all troops equipment and supplies to coincide with the exact arrival of combat units at the designated areas. Then Cohen was assigned to the highly sensitive secret "EMBARCO" at the U.S. Army Southern Base section at Wilton, Wilts, England. EMBARCO controlled all U.S. Logistical support for "Overlord" under the command of Colonel Chuck Broshous. On D-Day Cohen was designated as a courier to carry highly secret documents to the far shore of Normandy. He boarded a plane at Thorney Island, England. The plane made a forced landing as it was hit by flak. Cohen proceeded by Jeep transport through sniper fire and land mind hazards to the Overseas Message Center. He signed off documents and return to headquarters on June 7, 1944.