23rd Marine Regiment

23rd Marine Regiment
Unit name	23rd Marine Regiment
Caption	Shoulder sleeve insignia
Country	United States of America
Branch	United States Marine Corps Reserve
Type	Infantry regiment
Role	Amphibious assault, expeditionary operations
Size	Regiment
Command structure	4th Marine Division, Marine Forces Reserve
Garrison	Grand Rapids, Michigan
Motto	Semper Fidelis
Notable commanders	Christian F. Schilt

23rd Marine Regiment The 23rd Marine Regiment is a reserve infantry regiment of the United States Marine Corps organized under the 4th Marine Division and Marine Forces Reserve. The regiment has participated in major amphibious operations during the Pacific campaign, later serving in Cold War-era reserve activations, and has provided mobilized personnel for expeditionary deployments in the global war on terror and humanitarian crises. Its lineage ties connect it to campaigns such as the Gilbert and Marshall Islands operations, while its personnel have been recognized with unit and individual decorations.

History

The regiment was activated during World War II as part of expansion of the United States Marine Corps for combat in the Pacific War, joining the newly formed 4th Marine Division and preparing for operations in the Central Pacific Campaign. During the Guadalcanal aftermath and island-hopping strategy influenced by planners from Admiral Chester W. Nimitz's Pacific Ocean Areas command and staff officers from Fleet Marine Force Pacific, the regiment trained for amphibious assaults linked to doctrine developed from lessons at Battle of Tarawa and Battle of Saipan. After World War II demobilization, the regiment was reconstituted in the United States Marine Corps Reserve with ties to reserve centers in the Midwestern United States, aligning with strategic concepts emerging from the National Security Act of 1947 and subsequent force structure debates during the Cold War. Reserve activations and mobilizations during crises, including operations supporting Operation Desert Shield and the global campaigns following September 11 attacks, underscored the regiment's role in augmenting active forces.

Organization and units

The regiment falls under the command of the 4th Marine Division and Marine Forces Reserve with subordinate battalions organized as infantry, weapons, and logistics elements drawn from reserve centers across multiple states. Typical subordinate units have included infantry battalions based in the Great Lakes region, weapons companies equipped to support combined arms with coordination linked to 1st Marine Division and 3rd Marine Aircraft Wing elements during amphibious planning. Administrative alignment requires coordination with Marine Corps Systems Command for equipment and with Marine Corps Recruit Depot training centers for individual readiness standards. During mobilizations, the regiment integrates with expeditionary units coordinated through U.S. Pacific Command (now United States Indo-Pacific Command) and shore support from Naval Amphibious Forces elements.

World War II operations

During World War II the regiment earned distinction in operations across the Marshall Islands campaign and the Gilbert and Marshall Islands campaign, participating in assault landings that supported strategic objectives set by Joint Chiefs of Staff planners and executed under Admiral Raymond A. Spruance and Admiral William Halsey Jr.. The regiment conducted amphibious assaults employing doctrine refined after the Battle of Guadalcanal and in coordination with naval gunfire from units within United States Navy task forces and close air support from elements of the United States Army Air Forces. Combat actions placed regiment elements in engagements reflecting the larger operational art of the island-hopping strategy that culminated in advances toward Marianas Campaign objectives, interacting with logistics efforts managed by the Service of Supply and medical evacuation protocols shaped by experiences at Battle of Peleliu and Battle of Iwo Jima. Casualty evacuation, replacement, and reconstitution were influenced by policies from the Marine Corps Combat Replacement Center and theater-level commanders.

Postwar service and activations

Following World War II demobilization, the regiment was reorganized in the reserve component and participated in peacetime training alongside units of the United States Naval Reserve and Army Reserve for interoperability in joint operations and civil support missions. The regiment's reservists have mobilized to support operations associated with Operation Desert Shield and Operation Iraqi Freedom, integrating with active-duty formations during deployments under U.S. Central Command and logistics pipelines through Military Sealift Command. The unit has also provided forces for humanitarian assistance following regional crises, coordinating with agencies such as the Federal Emergency Management Agency and humanitarian elements of United States Agency for International Development when activated for domestic support.

Honors and awards

Elements of the regiment received unit citations and campaign streamers for participation in the Gilbert Islands campaign, Marshall Islands campaign, and related World War II actions recognized by the Navy Unit Commendation and Presidential Unit Citation precedence reflected in Marine Corps heraldry. Individual Marines have been decorated with awards administered by the Department of the Navy and the Department of Defense, including distinctions such as the Silver Star, Bronze Star Medal, and Purple Heart, reflecting valor, meritorious service, and wounds in action. The regiment's service has been commemorated in unit histories archived by the Marine Corps History Division and recognized by veteran organizations including the Marine Corps League.

Notable personnel and leadership

Commanders and notable Marines associated with the regiment include leaders whose careers intersected with higher-echelon commands and decorations from actions in the Pacific and postwar service. Officers and enlisted leaders advanced to positions within the Marine Corps, including billets at Quantico, Virginia training commands, staff positions at Headquarters Marine Corps, and joint assignments in Joint Chiefs of Staff planning cells. Distinguished alumni have been cited in histories compiled by the National Archives and Records Administration and oral histories preserved by the Library of Congress Veterans History Project.

Category:Infantry regiments of the United States Marine Corps Category:Military units and formations of the United States in World War II