For extraordinary heroism and courage as Executive Officer of Company B, 1st Battalion, 5th Marines, 1st Marine Division, during a frontal assault upon a strongly fortified enemy Japanese position along the coast of Guadalcanal, Solomon Islands, August 27, 1942. After organizing a volunteer party to advance and evacuate the wounded from the hazardous position well forward of the company, First Lieutenant Mcllhenny, armed only with a rifle, and while under heavy enemy mortar and machine gun fire, covered the advance and withdrawal of the rescue party, gallantly drawing enemy fire and silencing a Japanese machine gun nest. Although ill at the time and suffering shock from concussion of an enemy mortar shell, he returned to a vantage point close to enemy lines and, in the face of fierce sniper fire, acted as an observer, relaying accurate information necessary for fire control until ordered by his superior officer to leave his post. His great personal valor, above and beyond the call of duty, not only made possible the rescue of nine wounded men but also contributed to the success of Marine mortar fire.