The 2nd Battalion, 9th Marines were part of the reserve forces for the Battle of Iwo Jima and were committed to the action five days after D-Day. Among the Marines who distinguished themselves on Iwo Jima was Private Wilson D. Watson who received the Medal of Honor. After the island was secured, the unit was sent back to Guam where they underwent training for a possible invasion of the Japanese mainland. The invasion never occurred since hostilities between Japan and the United States came to an end. The 2nd Battalion, 9th Marines was sent to Camp Pendelton where, in December 1945, it was once again disbanded.