5th Marine Division ( United States ) The 5th Marine Division was a United States Marine Corps infantry division . Created during World War II , the 5th Division saw its first combat action during the Battle of Iwo Jima in World War II where it earned the Presidential Unit Citation as part of the invasion force awarded and sustained the highest number of casualties amongst the invasion force . The division was to be part of the planned invasion of the Japan homeland before Japan surrendered . The 5th Division was disbanded in 1946 . The 5th Division was reactivated in 1966 during the Vietnam War where its 13th , 26th , and 27th regiments under the command of the 3rd Marine Division ( Reinforced ) and 1st Marine Division ( Reinforced ) saw action in Vietnam until 19 March 1970 . The 26th Marine Regiment earned a Presidential Unit Citation for the Battle of Khe Sanh in 1968 . The 5th Division was formally deactivated at Camp Pendleton , California on 26 November 1969 . History . World War II . The 5th Marine Division was activated on Armistice Day , 11 November 1943 . The division ' s Headquarters Battalion officially began operating at Marine Corps Base Camp Pendleton on 1 December , at which time men and equipment began streaming into Camp Pendleton . The official activation date for the Division was 21 January 1944 . The division had a solid core of combat veterans from the beginning however there were many issues raising the total required number of Marines as the Marine Corps had to provide combat replacements to other divisions and staff the newly formed 6th Marine Division also . Among the personnel forming the new division were Marines from the former 1st Marine Parachute Regiment , the Raider Training Battalion , the Parachute Training School , West Coast , and the Parachute Replacement Company . Parts of the division began to deploy overseas to act as the reserve force during the Battle of Guam where they were not needed . Because of this they were sent to Camp Tarawa near Hilo , Hawaii for further training . After more extensive training the division loaded ships and left Hawaii in January 1945 . By mid - February they were sailing past Saipan headed for Iwo Jima . Iwo Jima . The 5th Division landed on Iwo Jima on 19 February 1945 . The division landed on the left northeast of Mount Suribachi and sustained heavy initial losses so much so that by that afternoon the 26th Marines had to be released as the division reserve . The 5th Marine Division would fight on Iwo Jima from 19 February until 18 March where they would sustain 1 , 098 killed in action and 2 , 974 wounded in action . This was the highest casualty rate amongst the Marine divisions involved in the invasion . The 5th Marine Division began loading onto ships on 18 March and finally left Iwo Jima on 27 March 1945 sailing for Hawaii . On 21 March 1945 the 5th Marine Division Cemetery was formally dedicated on Iwo Jima . Chaplains prayed , Major General Keller E . Rockey added a tribute to the dead and Lieutenant Roland B . Gittelsohn , U . S . Navy and a 5th Division chaplain , spoke of friends buried and " the ghastly price of freedom . . . " The flag was raised then lowered to half - mast . Taps was played echoing across the dark foreboding ash of Sulfur Island . Iwo Jima became an important support and emergency landing field for aircraft based out of the Marianas . In recognition of the 5th Marine Division ' s sacrifice in securing the island , the US Army Air Corps 9th Bombardment Group named a B - 29 " The Spearhead " , with elaborate nose art depicting the Division ' s insignia and the flag raising on Mt . Suribachi . The 5th Marine Division returned to Camp Tarawa , Hawaii and remained there until the end of the war . After the Japanese surrender they set sail for Japan where they occupied the southern island of Kyūshū . The division left Japan in November 1945 and arrived in San Diego , California the week of Christmas 1945 . The majority of the division ' s Marines were discharged shortly thereafter the division was deactivated on 5 February 1946 . Vietnam War . On 27 February 1966 , Secretary of Defense McNamara ordered the reactivation of the 5th Marine Division at Camp Pendleton on 1 March 1966 . The 5th Division headquarters was activated at Camp Pendleton , California , in June of that year . The 5th Division was composed of the 13th regiment of artillery , and the 26th , 27th , and 28th regiments of infantry . The 26th Marines was activated on 1 March with orders to ship immediately to South Vietnam . Each infantry battalion of the 26th Marines received eight weeks pre - deployment training at Camp Pendleton . The 26th Marines were based in Vietnam beginning in August 1966 until 19 March 1970 , but were never commanded by the 5th Division . By June 1967 , the 5th Division was ready to deploy anywhere . 1st Battalion , 26th Marines : Activated on 1 May 1966 . Moved out of Camp Pendleton on 6 July and was assigned to the 7th Fleet ' s Special Landing Force on 5 August . It participated in the 26th Marines first combat operation in Vietnam off the assault helicopter carrier USS Iwo Jima during Operation Deckhouse III and taking the regiments first four casualties . The 1 / 26 Marines was based in South Vietnam on 27 September 1966 . 2nd Battalion , 26th Marines : Activated on 1 June 1966 . Moved out of Camp Pendleton on 27 July and boarded the USS Bexar . The 2 / 26 Marines arrived in Danang , South Vietnam on 27 August 1966 . 3rd Battalion , 26th Marines : Activated on 1 July 1966 . Moved out of Camp Pendleton on 2 September and was assigned to the 7th Fleet ' s Special Landing Force on 4 October . The 3 / 26 Marines was based in Vietnam on 11 December 1966 . Kilo Battery , 13th Marines , landed at the mouth of the Cua Viet River in Vietnam in May 1967 . Alpha , Bravo , and Charlie 1 / 13 were present at the Battle of Khe Sahn in 1968 . While the 27th Marine Regiment would be sent to Vietnam in February 1968 , the 28th Marine Regiment would remain at Camp Pendleton throughout the Vietnam War . Battle of Khe Sahn & Tet Offensive , 1968 . 26th Marines : Participated in the Battle of Khe Sahn , 21 January to 9 July 1968 and was awarded a Presidential Unit Citation for its actions at Khe Sanh on 20 January to 1 April 1968 while attached to the 3rd Marine Division ( Reinforced ) . 27th Marines : In February 1968 , General William Westmoreland , the commander of U . S . forces in Vietnam asked for help in Vietnam because of the Communist Tet offensive . President Johnson then committed more troops to the war effort . On 12 February 1968 , the 27th Marines was ordered to Vietnam . The 27th Marines deployed to Vietnam on 17 to 19 February 1968 . The 27th Marines became the first Marine regiment to fly into a combat zone in Vietnam . The 3rd Battalion , 27th Marines , which deployed on 17 February , was awarded a Meritorious Unit Commendation for action during Operation Allen Brook at Go Noi Island on 17 to 28 February 1968 while attached to the 1st Marine Division ( Reinforced ) . During this operation , its members earned a Medal of Honor , 2 Navy Cross es , and several Silver Star Medal s and Bronze Star Medal s with Combat " V " s . In September 1968 , The 27th Marines , after serving seven months in country Vietnam , became the first major combat unit to come home from Vietnam . All first tour personnel were reassigned to other units in order to complete their tours . The 5th Division began deactivating its member units on 15 October 1969 . The 5th Division was formally deactivated on 26 November 1969 , and the men reformed into the 5th Marine Expeditionary Brigade . Medal of Honor recipients . 15 Marines and 2 Navy corpsmen assigned to the 5th Marine Division were awarded the Medal of Honor for World War II ( Iwo Jima ) . 12 were posthumously awarded . 2 Marines of the 26th and 27th Marines were posthumously awarded the Medal of Honor for the Vietnam War . Posthumous Vietnam War . Posthumous