1st Marine Division


The 1st Marine Division is a Marine division of the United States Marine Corps headquartered at Marine Corps Base Camp Pendleton, California. It is the ground combat element of the I Marine Expeditionary Force.
It is the oldest and largest active duty division in the United States Marine Corps, representing a combat-ready force of 22,000 personnel. It is one of three active duty divisions in the Marine Corps today and is a multi-role, expeditionary ground combat force. It is nicknamed "The Old Breed".

Mission

The division is employed as the ground combat element of the I Marine Expeditionary Force or may provide task-organized forces for assault operations and such operations as may be directed. The 1st Marine Division must be able to provide the ground amphibious forcible entry capability to the naval expeditionary force and to conduct subsequent land operations in any operational environment.

Organization

As of January 2025 1st Marine Division currently comprises a headquarters battalion, four regiments and five separate battalions as follows:

Inter-war years

The lineal forebear of the 1st Marine Division is the 1st Advance Base Brigade, which was activated on 23 December 1913 at Philadelphia, Pennsylvania.. The brigade consisted of the Fixed Defense Regiment and the Mobile Defense Regiment, later designated as the 1st and 2nd Regiments, 1st Brigade, respectively. In 1916, while deployed in Haiti, the two regiments were again redesignated, exchanging numerals, to then become the 2nd and 1st Regiments, 1st Brigade. Between April 1914 and August 1934, elements of the 1st Brigade participated in operations in Mexico, Haiti, the Dominican Republic, and Cuba, receiving campaign credit for service in each nation. While the 1st Brigade did not serve ashore in the European theater during the First World War, the brigade was awarded the World War I Victory Medal Streamer, with one bronze star, in recognition of the brigade's service during that conflict. On 16 September 1935, the brigade was redesignated as the 1st Marine Brigade and deployed to Guantanamo Bay, Cuba in October 1940.

World War II

The 1st Marine Division was activated aboard the on 1 February 1941. In May 1941, the 1st MARDIV relocated to Quantico, Virginia and Parris Island, South Carolina and in April 1942, the division began deploying to the Samoan Islands and Wellington, New Zealand. The division's units were scattered over the Pacific Ocean with the support elements and the 1st Marine Regiment transported en route to New Zealand on three ships, the USATs Ericsson, Barnett and Elliott from Naval Reserve Air Base Oakland to New Zealand, and later were landed on the island of Guadalcanal, part of the Japanese-occupied Solomon Islands, on 7 August 1942.
Initially, only the 7th Marine Regiment was in garrison on Western Samoa, with the 5th Marine Regiment having just encamped at Wellington after disembarking from USAT Wakefield, and the 1st Marine Regiment not scheduled to arrive in New Zealand until 11 July. The 1st Raider Battalion was on New Caledonia, and the 3rd Defense Battalion was in Pearl Harbor. All of the division's units, with the 11th Marines and 75mm howitzer armed 10th Marines battalion would rendezvous at British Fiji.
Due to the change in orders and shortage of attack and combat cargo vessels, all of the division's 2.5-ton trucks, M1918 155-mm howitzers and the sound and flash-ranging equipment needed for counter-battery fire had to be left in Wellington. Also, because the Wellington dock workers were on strike at the time, the Marines had to do all the load reconfiguration from administrative to combat configuration.
After eleven days of logistical challenges, the division, with 16,000 Marines, departed Wellington in eighty-nine ships embarked for the Solomon Islands with a sixty-day combat load which did not include tents, spare clothing or bedrolls, office equipment, unit muster rolls, or pay clerks. Other things not yet available to this first wave of Marine deployments were insect repellent and mosquito netting. Attached to the division was the 1st Parachute Battalion, which along with the rest of the division, conducted landing rehearsals from 28 to 30 July on Koro Island, which Major General Alexander Vandegrift described as a "disaster".
On 31 July the entire Marine task force was placed under the command of Vice Admiral Frank J. Fletcher's Task Force 61. The division as a whole would fight in the Guadalcanal campaign until relieved at 1400 on 9 December 1942 by the Army's Americal Division commanded by Lieutenant General Alexander Patch. This operation won the division its first of three World War II Presidential Unit Citations. The battle would cost the division 650 killed in action, 1,278 wounded in action with a further 8,580 contracting malaria and 31 missing in action. Others were awarded for the battles of Peleliu and Okinawa.
Following the Guadalcanal campaign, the division's Marines were sent to Melbourne, Australia for rest and refit. It was during this time that the division took the traditional Australian folk song "Waltzing Matilda" as its battle hymn. To this day, 1st Division Marines still ship out to this song being played.
The division would next see action during Operation Cartwheel which was the codename for the campaigns in Eastern New Guinea and New Britain. They came ashore at the Battle of Cape Gloucester on 26 December 1943 and fought on New Britain until March 1944 at such places as Suicide Creek and Ajar Ridge. During the course of the battle the division had 310 killed and 1,083 wounded. Following the battle they were sent to Pavuvu in the Russell Islands for rest and refitting.
The next battle for the 1st Marine Division would be the bloodiest yet at the Battle of Peleliu. They landed on 15 September 1944 as part of the III Amphibious Corps assault on the island. The division's commanding general, Major General William H. Rupertus had predicted the fighting would be, "...tough but short. It'll be over in three or four days – a fight like Tarawa. Rough but fast. Then we can go back to the rest area." Making a mockery of the prediction, the first week of the battle alone cost the division 3,946 casualties, during which time they secured the key airfield sites. The division fought on Peleliu for one month before being relieved. Some of the heaviest fighting of the entire war took place in places such as Bloody Nose Ridge and the central ridges of the island that made up the Umurbrogol Pocket. The month of fighting against the 14th Division on Peleliu cost the 1st Marine Division 1,252 dead and 5,274 wounded.
The final campaign the division would take part in during World War II would be the Battle of Okinawa. The strategic importance of Okinawa was that it provided a fleet anchorage, troop staging areas, and airfields in close proximity to Japan. The division landed on 1 April 1945 as part of the III Amphibious Corps. Its initial mission was, fighting alongside the 6th Marine Division, to clear the northern half of the island – that they were able to do expeditiously. The Army's XXIV Corps met much stiffer resistance in the south, and on 1 May 1945 the Marine division was moved south where it relieved the Army's 27th Infantry Division. The division was in heavy fighting on Okinawa until 22 June 1945, when the island was declared secure. The 1st Marine Division slugged it out with the Japanese 32nd Army at such places as Dakeshi Ridge, Wana Ridge, "Sugarloaf Hill" and Shuri Castle. Fighting on Okinawa cost the division 1,655 killed in action.
During the war, the division had five Seabee Battalions posted to it. The 6th NCB was attached to the 1st Marine Division on Guadalcanal. They were followed by the 19th Naval Construction Battalion which was assigned to the 17th Marines as the third battalion of the regiment. They landed at Cape Gloucester with the division. The 17th Marines were inactivated with the 19th NCB being reassigned. After that, the 33rd NCB was posted to the 1st for the assault on Peleliu and they were replaced by the 145th NCB for the invasion of Okinawa. On Peleliu, the 17th Special NCB was assigned to the 1st Pioneers as shore party. Together with the 16th Marines Field Depot they helped evacuate wounded and bury the dead for the 7th Marines. On the first night of the assault, nearly all of the 17th Seabees volunteered to hump ammo to the frontlines. They also reinforced the Marines in sections where directed, were used to crew a 37mm, and were utilized for several days. For their efforts, they received an official "well done". The 33rd NCB also had 202 Men assigned to the shore party.
Following the surrender of Japan, the division was sent to Northern China as the lead combat element of the III Amphibious Corps with the primary mission of preventing the People's Liberation Army from accepting the surrender of Japanese soldiers there, and to secure the region for the Nationalist Government. They landed at Taku on 30 September 1945 and would be based in Hebei Province in the cities of Tianjin and Beijing, and also on the Shandong Peninsula, with the Chinese Civil War between the Kuomintang and Chinese Communist Party raging around them. Most Marines in the division would be charged with guarding supply trains, bridges, and depots to keep food and coal moving into the cities. During this time they increasingly fought skirmishes with soldiers from the People's Liberation Army who raided ambushed, and harassed the railways and other infrastructure.
By the summer of 1946 the division was suffering the effects of demobilization and its combat efficiency had dropped below wartime standards; however, its commitments in China remained. As it became increasingly apparent that a complete collapse of truce negotiations among the Chinese factions was apparent, plans were laid for the withdrawal of all Marine units from Hebei. The last elements of the division finally left China on 1 September 1947.