The President of the United States of America, authorized by Act of Congress, July 9, 1918, takes pleasure in presenting the Distinguished Service Cross to Sergeant William Callahan (ASN: 1708546), United States Army, for extraordinary heroism in action while serving with Company E, 308th Infantry Regiment, 77th Division, American Expeditionary Forces, near Revillon, France, 9 September 1918. In order to clean out an enemy machine-gun nest which was holding up the advance of his company Sergeant Callahan volunteered and, with an officer crawled through the enemy wire into his lines, killed two of the enemy; and, although their position was discovered and the area was swept by machine-gun fire, he remained with the officer, killed an enemy machine gunner, and drove another away with his gun, and finally returned with information concerning enemy positions.