U.S. Marine Corps

The 1st Marine Division Service Company, Headquarters Battalion (1st MarDiv Svce Co HQBn), is a support unit within the storied 1st Marine Division of the United States Marine Corps. Formed during World War II, the Service Company has provided vital logistical, administrative, and supply support to division operations across major conflicts, including the Pacific campaigns, Korea, Vietnam, and the Middle East. Members of Service Company ensure the Headquarters Battalion and division command staff remain operational by handling transportation, maintenance, and essential services. Their behind-the-scenes efforts have been critical to the division’s success in both combat and peacetime operations.

The 3rd Marine Brigade was an expeditionary unit of the United States Marine Corps, activated at various times throughout the 20th century. During World War II, the brigade was briefly based at Kaneohe Bay, Hawaii, serving as a rapid reaction force for the defense of the Hawaiian Islands and as a staging element for operations in the Pacific Theater. Its presence at Kaneohe Bay contributed to the overall readiness and security of U.S. forces in the central Pacific following the attack on Pearl Harbor. The brigade was later reorganized and its personnel reassigned as the Marine Corps focused on offensive operations across the Pacific.

The 5th Battalion, 14th Marine Regiment (5/14th Marines) is a reserve artillery battalion of the United States Marine Corps. Activated during World War II, the battalion participated in the Pacific campaign, notably in the Battle of Okinawa, providing crucial fire support for ground forces. After being deactivated post-war, 5/14th Marines was reactivated as part of the Marine Corps Reserve, with its headquarters located in Seal Beach, California. In recent years, the battalion has supported operations in Iraq and Afghanistan, exemplifying its ongoing commitment to providing artillery support to Marine Air-Ground Task Forces.

Headquarters and Maintenance Squadron 16 (H&MS-16) was a United States Marine Corps aviation support unit established to provide logistics, maintenance, and administrative support to Marine Aircraft Group 16 (MAG-16). Activated during the Vietnam War, H&MS-16 played a crucial role at bases such as Marble Mountain Air Facility, supporting helicopter squadrons by ensuring aircraft readiness through maintenance and supply operations. The squadron’s efforts contributed significantly to the operational effectiveness of helicopter missions, including troop transport, medical evacuation, and logistical resupply. After the Vietnam War, H&MS-16 continued to support Marine aviation until it was eventually redesignated as part of the Marine Aviation Logistics Squadron (MALS) reorganization.

Marine Medium Helicopter Squadron 264 (HMM-264), also known as the "Black Knights," was activated on June 30, 1959. The squadron initially operated the Sikorsky H-34 helicopter before transitioning to the CH-46 Sea Knight, which became its primary aircraft for decades. HMM-264 participated in numerous major operations, including deployments to Lebanon, Operation Desert Storm, and humanitarian missions in Africa and the Caribbean. The unit was deactivated in May 2015 as part of the Marine Corps' transition to the MV-22 Osprey and the restructuring of aviation assets.

HMM-364, known as the "Purple Foxes," is a distinguished United States Marine Corps helicopter squadron originally activated in 1961. The unit first saw extensive combat during the Vietnam War, providing crucial assault support and medevac missions with their CH-46 Sea Knight helicopters. Renowned for their bravery, HMM-364 participated in numerous major operations, including the Siege of Khe Sanh and Operation Dewey Canyon. After Vietnam, the squadron continued to serve in various global conflicts and humanitarian missions, exemplifying the Marine Corps' commitment to rapid-response aviation support. The unit was redesignated as VMM-364 in 2012, transitioning to the MV-22B Osprey tiltrotor aircraft.

Headquarters Battalion, 3rd Marine Division (HQBN 3rd MarDiv), based in Okinawa, Japan, traces its roots to the activation of the 3rd Marine Division in 1942 during World War II. The unit played a vital role in providing command and control, administrative, and logistical support to the division throughout major Pacific campaigns, including the Battle of Iwo Jima. After the war, HQBN was reactivated and relocated several times, ultimately establishing a longstanding presence on Okinawa as part of the United States’ forward-deployed forces in the Indo-Pacific region. Today, HQBN 3rd MarDiv continues to support Marine operations and readiness, serving as a critical element in maintaining regional stability and rapid response capabilities.

Marine Air Control Squadron 4 (MACS-4) is a United States Marine Corps aviation command and control unit that was originally activated during World War II in 1944. The squadron has a storied history, providing air surveillance, air traffic control, and air defense capabilities in support of Marine Corps operations. MACS-4 played significant roles during the Korean War, Vietnam War, and has participated in numerous exercises and operations throughout the Asia-Pacific region. Today, MACS-4 remains a key component of the 1st Marine Aircraft Wing, supporting expeditionary air operations and enhancing the Corps' ability to control the battlespace.

Marine Air Control Squadron 5 (MACS-5) was a United States Marine Corps aviation command and control unit. Activated during World War II, the squadron provided aerial surveillance, airspace management, and early warning capabilities for Marine aviation operations. Throughout its history, MACS-5 supported various exercises and deployments, contributing significantly to the Marine Corps’ air defense missions. The unit was eventually deactivated as part of post-Cold War force reductions, but its legacy remains in the advancements it brought to Marine Corps air command and control systems.

Marine Aircraft Group 49 (MAG-49) is a United States Marine Corps Reserve aviation unit established in 1969. Headquartered at Joint Base McGuire-Dix-Lakehurst, New Jersey, MAG-49 provides aviation combat element support, including assault support, heavy lift, and aviation logistics, to Marine Forces Reserve. Throughout its history, MAG-49 has participated in numerous training exercises and mobilizations, supporting both domestic and overseas operations such as Operation Desert Storm and Operation Iraqi Freedom. The group’s diverse squadrons operate various rotary and fixed-wing aircraft, maintaining readiness to augment active-duty Marine aviation forces when called upon.

Marine Helicopter Squadron One (HMX-1) was established on December 1, 1947, at Marine Corps Air Facility Quantico, Virginia. Originally tasked with testing and developing helicopter tactics and equipment, HMX-1 soon took on the unique mission of providing helicopter transport for the President of the United States, a role it has fulfilled since 1957. The squadron is best known for operating the "Marine One" helicopters, ensuring safe and secure executive transport. Over the decades, HMX-1 has expanded its mission to include support for visiting heads of state, dignitaries, and other VIPs, while maintaining a standard of excellence in both operational capability and ceremonial duties.

Marine Corps Air Station (MCAS) Kaneohe Bay, located on the island of Oahu, Hawaii, was originally established in 1939 as a U.S. Navy air station. On December 7, 1941, it was one of the first sites attacked during the Japanese raid on Pearl Harbor, suffering significant damage and casualties. After World War II, the base played a key role in supporting Pacific operations and was officially transferred to the United States Marine Corps in 1952. Since then, MCAS Kaneohe Bay has served as a crucial hub for Marine Corps aviation, training, and expeditionary operations throughout the Indo-Pacific region.

Marine Wing Support Squadron 172 (MWSS-172), known as the “Firehawks,” was activated on 16 April 1986 at Marine Corps Air Station Futenma, Okinawa, Japan. The squadron is a part of Marine Aircraft Group 36, 1st Marine Aircraft Wing, and provides essential aviation ground support for Marine Corps aviation operations throughout the Asia-Pacific region. MWSS-172 has supported numerous exercises, humanitarian missions, and real-world contingencies, including operations in the Philippines, Thailand, and disaster relief efforts such as Operation Tomodachi following the 2011 Japan earthquake and tsunami. Through its diverse mission sets, MWSS-172 continues to play a critical role in maintaining the operational readiness and effectiveness of Marine aviation forces in the Indo-Pacific.

United States Naval Mobile Construction Battalion 11 (USNMCB 11), also known as "Seabees," was commissioned during World War II in 1942. The battalion played a crucial role in constructing bases, airfields, and infrastructure in the Pacific Theater, supporting major operations such as those in Guadalcanal and the Solomon Islands. Reactivated for the Vietnam War, NMCB 11 built vital facilities, roads, and defensive positions throughout Southeast Asia. The unit has since continued to serve in various global deployments, providing critical construction and humanitarian support in both peacetime and conflict.

Marine Fighter Attack Squadron 334 (VMFA-334), known as the “Falcons,” was a United States Marine Corps fighter attack squadron. Initially activated during World War II as VMSB-334, the unit transitioned through various aircraft and roles before becoming VMFA-334. During the Vietnam War, the squadron flew F-4 Phantom II jets and was heavily engaged in combat operations from 1967 to 1970, earning multiple commendations for its actions. VMFA-334 was deactivated in 1971, marking the end of its distinguished service.

Marine Fighter Attack Squadron 513 (VMFA-513), known as the "Flying Nightmares," was originally commissioned in 1944 as VMF-513. The squadron saw combat in World War II, the Korean War—where it became the first Marine squadron to fly jet aircraft in combat—and the Vietnam War, providing close air support and night-fighting capabilities. In the 1980s, VMFA-513 transitioned to flying the AV-8B Harrier II, becoming one of the Marine Corps’ premier vertical/short takeoff and landing (V/STOL) attack squadrons. The squadron participated in Operations Desert Storm, Iraqi Freedom, and Enduring Freedom before being deactivated in 2013.

Marine Observation Squadron 1 (VMO-1) was activated in July 1943 during World War II, providing aerial observation and artillery spotting for Marine ground forces in the Pacific Theater. The squadron flew a variety of aircraft, including the OY-1 Sentinel, supporting campaigns such as Saipan, Tinian, and Okinawa. After the war, VMO-1 was based at Marine Corps Air Station New River, North Carolina, transitioning to helicopters and later the OV-10 Bronco for reconnaissance and light attack missions. The unit served with distinction through the Cold War and participated in operations such as Desert Storm before being deactivated in 1993.

The 1st 155mm Gun Battalion (Self-Propelled), stationed at 29 Palms, California, was a U.S. Army artillery unit active during the Cold War era. Equipped with self-propelled 155mm guns, the battalion provided heavy fire support for maneuver units during training exercises and potential combat operations. Based at the Marine Corps Air Ground Combat Center, Twentynine Palms, the unit played a key role in joint Army-Marine Corps artillery cooperation in the desert environment. The battalion’s mission focused on rapid, mobile artillery response, contributing significantly to the development of combined-arms tactics in the post–World War II period.

The 1st Battalion, 13th Marines (1/13) is an artillery battalion of the United States Marine Corps, first activated during World War II in February 1943. The battalion served with distinction in the Pacific Theater, participating in key campaigns such as the battles of Iwo Jima and Okinawa. After World War II, 1/13 was deactivated and reactivated several times, notably serving during the Vietnam War from 1966 to 1970, providing vital fire support. The unit has continued to serve in various capacities, supporting Marine operations and maintaining readiness as part of the 13th Marine Regiment.

The 2nd Battalion, 26th Marines (2/26) was an infantry battalion of the United States Marine Corps, first activated during World War II in 1944. The battalion saw intense combat in the Battle of Iwo Jima, contributing significantly to the capture of the island. Reactivated for the Vietnam War, 2/26 participated in numerous major operations, including the defense of Khe Sanh during the 1968 siege. The battalion was deactivated in 1970 following its return from Vietnam, having earned a distinguished combat record.

The **31st Marine Expeditionary Unit (31st MEU)**, activated in 1967, is the United States Marine Corps’ only continuously forward-deployed MEU, based out of Okinawa, Japan. Throughout its history, the 31st MEU has participated in numerous operations across the Indo-Pacific region, including humanitarian assistance, disaster relief, and combat missions such as Operation Desert Storm and Operation Iraqi Freedom. Renowned for its rapid-response capability, the unit frequently conducts training exercises with regional allies to strengthen partnerships and ensure regional security. Today, the 31st MEU remains a vital part of the U.S. military’s commitment to maintaining stability and readiness in the Asia-Pacific theater.

The 3rd Battalion, 7th Marines (3/7) is an infantry battalion of the United States Marine Corps, established in 1941. The unit saw distinguished service during World War II, participating in pivotal battles such as Guadalcanal, Peleliu, and Okinawa. During the Korean War, 3/7 fought in major engagements including the Battle of Chosin Reservoir. In recent history, the battalion has deployed extensively to Iraq and Afghanistan as part of Operation Iraqi Freedom and Operation Enduring Freedom, earning a reputation for effectiveness in combat and counterinsurgency operations.

The 4th Supply Battalion, a unit of the United States Marine Corps Reserve, was activated to provide essential supply and logistics support to Marine forces. Headquartered in Newport News, Virginia, the battalion plays a crucial role in ensuring combat readiness by managing the procurement, storage, and distribution of military supplies and equipment. Over the years, 4th Supply Battalion has supported numerous training exercises, mobilizations, and overseas operations, including deployments in support of Operations Desert Storm, Iraqi Freedom, and Enduring Freedom. The unit’s commitment to excellence has earned it recognition for its efficiency and reliability in sustaining Marine Corps missions worldwide.

The **Combined Action Program (CAP) Marines** were a unique unit formed by the United States Marine Corps during the Vietnam War, beginning in 1965. Their mission was to integrate small groups of Marines with local South Vietnamese Popular Forces in rural villages, providing both military training and security against Viet Cong insurgents. CAP Marines not only engaged in combat operations but also worked to win the "hearts and minds" of the local population through civic action and community engagement. The program was considered innovative for its emphasis on counterinsurgency and partnership, and it left a lasting legacy on U.S. military doctrine regarding irregular warfare.