The President of the United States of America takes pleasure in presenting the Silver Star to Corporal Richard O. Mack (MCSN: 443172), United States Marine Corps, for conspicuous gallantry and intrepidity while serving with the Second Battalion, Fourth Marines (Reinforced), First Provisional Marine brigade, Third Amphibious Corps, during action against enemy Japanese forces on Guam, Mariana Islands, 21 July 1944. When his squad was pinned down by an enemy machine gun, Corporal Mack moved within range of the Japanese to locate the machine-gun nest in a concealed and well-protected dugout. Calling for the enemy’s surrender and receiving no answer, he moved forward into the dugout to annihilate all the occupants and permit his squad and company to continue their advance. His aggressive fighting spirit and devotion to duty reflect the highest credit upon Corporal Mack and the United States Naval Service.