This East Coast echelon moved to Pendleton by train and transit of the Panama Canal in July and August 1943.

When all the units were finally together, the 4th Marine Division was formally activated on 14 August 1943, with Major General Harry Schmidt in command.

After intensive training, 23rd Marines shipped out on 13 January 1944, and in 13 months made four major amphibious assaults, in the battles of Kwajalein (Roi-Namur), Saipan, Tinian, and Iwo Jima, with the division suffering more than 17,000 casualties.

An account [citation needed] of 23rd Marines attack during the battle of Roi-Namur: "As dawn broke on D plus 1 (February 1, 1944), the LVT's waddled out of the jaws of the LST's and took up their circling, while the air strikes and naval bombardment mounted in fury.

After the earth-shaking barrage of naval shells and aerial bombs, climaxed by a deluge of rockets fired from LCI's, opposition on Roi was comparatively light, and the 0-1 line was reached at 1217.

The twisted steel skeletons of the hangars and the shattered remnants of the Jap planes were overrun, and the northern edge of the island was reached by 1800.

3d Battalion, 23rd Marines was assigned the G-Day missions of (1) providing security in the division zone forward of the Saudi defensive berm, which was located on the Saudi-Kuwait border, prior to G-Day; (2) passing through the breach lanes, and: (3) clearing its zone of action to support the attack north, and (4) screening to the northeast in order to allow 3d Battalion, 10th Marines (3/10) to establish artillery firing positions to provide preparation fires for offensive operations.

Phase Two was the introduction of one motorized infantry company, the battalion command element, and the 81 mm mortar platoon in the forward sector.

[6] On 22 February 1991 (G-Day minus two), 3/23 commenced combat operations as bulldozers cut three gaps in the Saudi berm to allow 3/23 and 3/10 to execute their missions.

This required the 81 mm mortar element to move forward of their assigned position in order to range the target for back-up marking capability.

However, smoke and haze from the burning oil field obscured the target from the FAC, making laser designation impossible.

Upon receiving incoming small arms rounds, Company H deployed to clear its zone of sniper and harassing fire.

The exact number of kills could not be determined due to the darkness, smoke, and numerous secondary explosions; however, it was readily apparent that these vehicles had been well stocked with munitions.

At 2330 on 26 February 1991, 3/23 was subsequently directed to continue clearing the farm complex from which fire had been received the previous day.

The operation was ceased and the battalion was directed to be prepared to execute the clearing mission in Al Shadadiyah, Kuwait the following day.

[6] 3/23 was mobilized on 5 March 2003, and deployed to Iraq with the 2nd Marine Division's Task Force Tarawa located in Al Kut.

Commanded by LtCol David Couvillon of Brusly, Louisiana, 3/23 conducted a relief-in-place with Task Force Tarawa, becoming responsible for the entire Wasit Province of Iraq.

LtCol Couvillon, acting also as Military Provincial Governor, and the Marines of 3/23 (supported by Marine and Army Civil Affairs Groups, as well as an Army Military Police Company) set about reestablishing government services, security actions, humanitarian actions, border security (Iraq/Iran), and general governance until relieved by a Ukrainian Infantry Brigade in September 2003.

They were then stationed in Camp Lejeune, NC to begin training for upcoming Combat Operations in Al Anbar, Iraq.

3/23 and all supporting units deployed to Haditha, Iraq,[7] in late September 2007, conducting Counter-IED Operations, patrols, convoys, raids, and basic Support and Stability Operations throughout Haditha and surrounding Al Anbar areas until April 2008, when they returned to the United States and demobilized.

It is the largest exercise within the U.S. Africa Command area of responsibility, and is designed to promote interoperability and mutual understanding of each nation's military tactics, techniques and procedures.

This article incorporates public domain material from websites or documents of the United States Marine Corps.