On 29 August 2025, the United States Marine Corps Reserve marks 109 years of service to the Nation. Born on 29 August 1916 with the Naval Appropriations Act, the Marine Corps Reserve has grown from a handful of Marines into a force that routinely augments and reinforces the active component in crises, wars, and humanitarian missions around the globe.

Origins and World War I

At its founding, the Reserve numbered just three officers and 32 enlisted Marines. By the end of World War I, more than 6,000 Marines had served in the Reserve, establishing the citizen-Marine tradition that continues today.

World War II: Mass Mobilization and Clarified History

During World War II, Marine reservists mobilized in large numbers for combat operations across the Pacific. Many sources long repeated that “~70%” of WWII Marines were reservists; Marine Corps historians have since clarified that the organized USMCR in 1940 was about 16,400, and ~15,000 were mobilized in 1940–41, with subsequent wartime accessions rapidly expanding the force. The bottom line: reservists were indispensable, but the oft-quoted percentage is misleading—historical precision honors their service more accurately.

Korea: Rapid Activation

When war broke out in 1950, the Marine Corps executed a complete mobilization of the organized ground reserve in just 53 days (20 July–11 September 1950). Reservists formed a significant portion of the force that executed the Inchon landing—about 17% of the Marines who went ashore were reservists.

Cold War, Vietnam, and Post-Cold War

From Berlin and the Cuban Missile Crisis to Vietnam, Haiti, and Bosnia, U.S. reservists were called to active duty multiple times, reflecting the Nation’s reliance on the Reserve in both deterrence and combat operations.

21st-Century Wars: An Operational Reserve

After 9/11, the Marine Corps Reserve shifted decisively from a “strategic” to an operational reserve. In Operation Iraqi Freedom, for example, roughly 17,000 Marine reservists were activated between January and May 2003 on top of earlier call-ups—evidence of sustained, large-scale integration with the active force.

Distinct Capabilities and Today’s Force

Marine reservists train to the same standards and MOSs as their active-duty counterparts and bring specialized civilian skills that strengthen the Corps—civil affairs, communications, intelligence, legal, medical, and even field historians, a capability uniquely manned by Marine reservists. Their ethos is captured in the Marine Forces Reserve motto: “Relevant, Ready, Responsive.”

Headquarters for Marine Forces Reserve is in New Orleans, Louisiana, at the Marine Corps Support Facility—a purpose-built complex that anchors Reserve command and control and tenant units.

Enduring Values, Enduring Impact

From Belleau Wood legacies to Fallujah and beyond, citizen-Marines have exemplified the Corps’ core values of honor, courage, and commitment, proving that part-time status has never meant part-time standards. As an integrated Total Force, the Reserve extends the reach and endurance of the Marine Corps across the full spectrum of operations—combat, crisis response, and humanitarian relief.

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A Birthday Worth Celebrating

For 109 years, the Marine Corps Reserve has stood the watch—answering every call, closing every gap, and returning to families, classrooms, job sites, and communities with quiet professionalism. On this anniversary, we honor all who served in the Reserve—past and present—and the families and employers who make their service possible.

**Happy 109th Birthday, Marine Corps Reserve.

Relevant, Ready, Responsive