 The <unk> Marine Division began operating in Vietnam when on March 6 , 1965 , they opened a Marine <unk> at the Da <unk> Air Base . On July 4 , 1965 , 2nd Battalion , 9th Marines were ordered to Vietnam from Okinawa . 2nd Battalion , 9th Marines fought battles in or around <unk> , <unk> , <unk> <unk> , <unk> <unk> , Camp Carroll , Cam <unk> , Con <unk> , Than Cam Son , Quảng <unk> , <unk> <unk> , <unk> Combat Base and what is considered by many as their most vicious engagement , the Battle of Khe Sanh . 
