1 November 1943 saw the division land as part of the Battle of Bougainville and fight on the island until their last unit to arrive, the 21st Marine Regiment, embarked on 9 January 1944.

During these 21 days of fighting, the division captured over 60 square miles (160 km2) of territory and killed over 5,000 enemy soldiers.

[7] The division remained on the island of Guam for training, until it embarked as part of the landing force for the Battle of Iwo Jima.

[citation needed] The division was reactivated on 7 January 1952 at Camp Pendleton, California, using the assets of the 3d Marine Brigade activated in June 1951.

Immediately after its activation and still in its organizational state, the division began intensive combat training, including new tactics and maneuvers based on lessons learned in the then-ongoing Korean War.

During the remaining part of 1952 elements of the division participated in numerous exercises and training problems, including vertical envelopment (helicopter landing), airborne operations and attack, and defense against atomic weapons and missiles.

In October 1966, then commanding general Lewis W. Walt was ordered to establish strong points just south of the Vietnamese Demilitarized Zone (DMZ).

At the same time the division was also building outposts along the southern half of the DMZ at Con Thien, Gio Linh, Cam Lộ and Đông Hà.

In late 1967 the headquarters moved again from Phu Bai to Đông Hà in the Quang Tri Province and more outposts were opened.

On November 14, 1967, the 3rd Marine Division commander Major General Bruno Hochmuth was killed northwest of Huế in a helicopter crash.

For extraordinary heroism in the Republic of Vietnam from 8 March 1965 to 15 September 1967, the division was awarded the Navy Presidential Unit Citation.

At the time, 3rd Marine Division intelligence estimated the combat strength of PAVN and Viet Cong (VC) forces in the DMZ area was 40,943 troops.

This included daily attempts at interdiction of naval traffic on the Cua Viet River near Đông Hà.

BLT 2nd Battalion, 4th Marines, the Landing Force of SLF A, remained under operational control of the division throughout the month.

[19] The division departed South Vietnam in November 1969 with more than 20 Marines having received the Medal of Honor and moved to Camp Courtney, Okinawa, where it is presently located.

The regiment, which became known as task Force Taro in honor of the state and people of Hawaii, became the first American unit to be engaged by Iraqi artillery, rocket and missile fire on 18 January 1991.

Task Force Taro countered the Iraqi supporting attacks by conducting artillery raids into Kuwait as the first ground offensive actions of the war.

From July 2004 through April 2005, Charlie Battery, 1st Battalion 12th Marines, deployed in support of Operation Iraqi Freedom.