5th Marines

5th Marines

The 5th Marines is an infantry regiment of the United States Marine Corps with a lineage stretching from World War I through contemporary operations. The regiment served in major 20th- and 21st-century campaigns, linking deployments across Western Front (World War I), World War II, Korean War, Vietnam War, Gulf War, and the War in Afghanistan (2001–2021). Its institutional history intersects with premier formations and events including the 1st Marine Division, 2nd Marine Division, Battle of Belleau Wood, Battle of Guadalcanal, and Battle of Chosin Reservoir.

History

Constituted amid American mobilization in 1917, the regiment deployed to the Western Front (World War I) and participated in the Second Battle of the Marne, the Battle of Belleau Wood, and the Meuse-Argonne Offensive. Between wars it was part of the postwar occupation of Germany and interwar expeditionary actions associated with the Banana Wars. In World War II the regiment fought in the Pacific campaigns at Guadalcanal, Cape Gloucester, Peleliu, and Okinawa as elements of the 1st Marine Division. During the Korean War the regiment conducted amphibious assault operations in concert with the Battle of Inchon and later endured the withdrawal at the Chosin Reservoir during the Chinese People's Volunteer Army intervention. In Vietnam War deployments the regiment operated from bases such as Phu Bai, engaging in counterinsurgency and conventional actions including operations near Hue and along the DMZ (Demilitarized Zone). In the post–Cold War era the regiment was mobilized for Operation Desert Storm, Operation Iraqi Freedom, and multiple rotations to Helmand Province and Kabul during the War in Afghanistan (2001–2021), integrating with Marine Expeditionary Brigade and Multinational Force commands.

Organization and Structure

The regiment is organized under the 1st Marine Division and traditionally comprises a regimental headquarters and three infantry battalions, a weapons company, and logistics elements. Battalions have been designated as 1st Battalion, 2nd Battalion, and 3rd Battalion within the regiment and have deployed as part of Marine Amphibious Unit and Marine Expeditionary Unit taskings embarked aboard amphibious assault ship classes such as Tarawa-class amphibious assault ship and Wasp-class amphibious assault ship. Command relationships have shifted between higher echelons including the Fleet Marine Force and the II Marine Expeditionary Force depending on theater requirements. The regiment integrates combined arms with attachments from Light Armored Reconnaissance Battalion, Tank Battalion, Combat Engineer Company, and Artillery Regiment elements such as the 11th Marines for fire support. Training cycles align with Marine Corps Combat Instructor programs, Advanced Infantry Training Battalion curricula, and joint exercises like Operation Steel Knight and multinational exercises with NATO partners.

Combat Operations

During World War I the regiment’s actions at Belleau Wood contributed to the development of Marine infantry doctrine and earned citations from Allied commands such as the French Republic and interaction with units like the 2nd Division (United States Army). In World War II sustained jungle and island warfare against the Imperial Japanese Army at Guadalcanal and Peleliu tested amphibious assault concepts alongside naval gunfire support from United States Navy task forces. The Korean War saw combined U.S. Marine and Army operations amid harsh winter conditions confronting forces of the Korean People's Army and the People's Volunteer Army. In Vietnam the regiment participated in search-and-destroy missions, pacification efforts, and conventional engagements against Army of the Republic of Vietnam and People's Army of Vietnam formations. In the 1991 Gulf War the regiment executed maneuver operations as part of the coalition offensive against Iraq and in the 2003 Iraq War conducted stability and combat operations during Operation Iraqi Freedom. In Afghanistan the regiment’s battalions engaged insurgent networks including Taliban forces, conducted partnered operations with Afghan National Army, and supported provincial reconstruction teams and counterinsurgency doctrine promulgated by United States Central Command.

Honors and Decorations

The regiment and its subordinate units have received unit citations and campaign streamers from multiple nations and commands. Recognitions include Presidential Unit Citation (United States), Navy Unit Commendation, and decorations awarded by allied commands such as citations from the French Republic for World War I service. Campaign streamers enumerate participation in the Aisne-Marne Offensive, Sicily Campaign-adjacent operations in broader theater contexts, Pacific campaigns including Palau and Ryukyu Islands, the Korean War campaigns, multiple phases of the Vietnam War, the Southwest Asia Campaign during the Gulf War, and the Iraq War and War in Afghanistan (2001–2021). Individual Marine decorations associated with regiment actions include the Medal of Honor, Navy Cross, and Silver Star across conflicts.

Notable Members and Commanders

The regiment’s ranks have included decorated officers and enlisted Marines who later influenced Marine Corps doctrine and national policy. Commanders and members have been cross-referenced with other prominent figures and units such as leaders who served in the 1st Marine Division, recipients of the Medal of Honor during Belleau Wood and Iwo Jima-era campaigns, and postwar figures associated with institutions like the National Security Council and United States Naval Academy. Notable names connected by service or command include individuals recognized in Marine Corps historiography and biographies preserved in collections at the Marine Corps History Division, National Archives and Records Administration, and museum holdings such as the National Museum of the Marine Corps.

Category:Infantry regiments of the United States Marine Corps