United States Army infantry regiments

United States Army infantry regiments
Unit name	United States Army infantry regiments
Caption	Soldiers of an infantry regiment during a combined arms exercise
Dates	18th century–present
Country	United States
Branch	United States Army
Type	Infantry
Role	Close combat, maneuver, security
Size	Regimental, battalion
Garrison	Various

United States Army infantry regiments are traditional tactical and administrative formations that have provided Continental Army-era lineage through the American Revolutionary War, the War of 1812, the Mexican–American War, the American Civil War, Spanish–American War, World War I, World War II, the Korean War, the Vietnam War, the Gulf War, the War in Afghanistan (2001–2021), and the Iraq War. Regiments have served under higher commands such as Infantry Division (United States), Armored Division (United States), United States Army Forces Command, and United States Army Pacific, adapting to doctrinal shifts from line infantry to light, airborne, air assault, and Stryker infantry roles. Over centuries regimental identity has been preserved through distinctive insignia, battle honors, and veterans’ associations like the Veterans of Foreign Wars and the American Legion.

History

Regimental origins trace to the Continental Army raised by Continental Congress and the provincial regiments raised by colonial governments such as Massachusetts Bay Colony and Virginia Colony, which later influenced organization during the War of 1812 and reforms under Secretary of War Henry Knox. The Civil War era saw regiments like the 20th Maine Volunteer Infantry Regiment and the 54th Massachusetts Infantry Regiment demonstrate the importance of regimental cohesion at Gettysburg Campaign and Fort Wagner (1863). The establishment of the United States Regular Army and the 1903 reforms by Secretary of War Elihu Root professionalized regimental staff work ahead of engagements in Philippine–American War and Pancho Villa Expedition. World War I brought the regiment into combined-arms challenges at Meuse–Argonne Offensive and the regiment-centric structure persisted into World War II with actions at Normandy landings, Anzio landings, and Battle of the Bulge. Cold War transformations and conflicts in Korean War and Vietnam War saw regiments adopting mechanized and air assault roles established by leaders like General Maxwell D. Taylor and initiatives such as the Pentomic Division experiment. Post-9/11 operations in Operation Enduring Freedom and Operation Iraqi Freedom prompted regimental rotations, embedded training teams, and interagency cooperation with units like 1st Cavalry Division and 82nd Airborne Division.

Organization and Structure

Historically regiments comprised multiple battalions under a regimental headquarters, a pattern seen in the 25th Infantry Regiment (United States), the 3rd Infantry Regiment (United States) and the 501st Infantry Regiment (United States). Under the United States Army Regimental System and the Combat Arms Regimental System units maintain lineage while battalions may be assigned to brigade combat teams such as the 1st Brigade Combat Team, 1st Infantry Division or the 3rd Brigade Combat Team, 4th Infantry Division. Regimental headquarters elements coordinate logistics, intelligence, and fires with support from Field Artillery Branch (United States), Ordnance Corps (United States Army), and Signal Corps (United States Army). Specialized regiments include Ranger Regiment (United States Army Rangers), 101st Airborne Division (United States), and 10th Mountain Division-affiliated infantry battalions configured for light, mechanized, airborne, or air assault missions. Distinctive unit insignia and regimental colors are administered under the U.S. Army Center of Military History and the Institute of Heraldry (United States).

Lineage and Honors

Regimental lineage records are maintained showing descent from early Continental units through redesignations and consolidations, as documented by the Center of Military History (United States Army). Battle streamers, campaign credit, and awards such as the Presidential Unit Citation, the Valorous Unit Award, and the Meritorious Unit Commendation attach to regiments and their subordinate battalions. Prominent decorations reflect campaigns including Normandy campaign, Anzio campaign, Iwo Jima, Chosin Reservoir, Tet Offensive, Operation Anaconda, and Second Battle of Fallujah. Regimental lineage often incorporates veterans’ organizations like the Association of the United States Army branch chapters, fostering historical continuity and commemorative events at sites such as the National Infantry Museum and battlefield memorials at Antietam National Battlefield.

Notable Regiments and Campaigns

Famous regular and volunteer regiments include the 1st Infantry Regiment (United States), 7th Infantry Regiment (United States), 3rd Infantry Regiment (The Old Guard), 15th Infantry Regiment (The Old Guard), 16th Infantry Regiment (United States), 20th Infantry Regiment (United States), 23rd Infantry Regiment (United States), 24th Infantry Regiment (United States), 27th Infantry Regiment (United States), 29th Infantry Regiment (United States), and the 187th Infantry Regiment (Airborne). Distinguished campaigns involve regiments at Gettysburg, Antietam, Santiago de Cuba, Belleau Wood, Meuse–Argonne Offensive, D-Day landings, Saipan campaign, Leyte campaign, Pusan Perimeter, Battle of Pork Chop Hill, Ia Drang Valley, Hamburger Hill, Operation Desert Storm, and key actions in Helmand Province and Mosul.

Equipment and Doctrine

Infantry regiments employ small arms and systems such as the M4 carbine, M249 light machine gun, M240 machine gun, M2 Browning machine gun, Mk 19 grenade launcher, M16 rifle, M14 rifle, squad anti-armor weapons like the Javelin (missile), FGM-148 Javelin, and crew-served systems mounted on Stryker (vehicle), M2 Bradley, and M1 Abrams when attached to mechanized formations. Doctrine evolves through publications from the United States Army Combined Arms Center and field manuals like Field Manual 3-21 (Infantry Operations), integrating concepts from AirLand Battle to Full Spectrum Operations and contemporary multi-domain operations advocated by U.S. Army Futures Command.

Recruitment, Training, and Personnel

Recruitment funnels soldiers into infantry MOSs such as 11B (Infantryman) and 11C (Indirect Fire Infantryman), with initial training at centers including Fort Benning, Fort Moore, Fort Leonard Wood, Fort Polk, and Fort Jackson. Advanced individual training, Ranger School at Camp Rogers (Fort Benning), Airborne School at Fort Moore, and unit qualifications prepare regimental soldiers for roles in Special Operations Command (United States)-adjacent missions, multinational exercises like Operation Bright Star, and joint deployments with United States Marine Corps and United Kingdom Armed Forces partners. Personnel management aligns with policies from Department of the Army headquarters and career guidance from Human Resources Command (United States Army).

Modern Role and Reorganization

Contemporary regiments exist largely as lineal organizations with battalions assigned to brigade combat teams under modularization initiatives linked to Modular Force reforms and the Army 2020 and Force 2030 planning cycles. Reorganizations have produced light infantry, Stryker brigade combat team, and air assault infantry formations supporting operations in Europe, Indo-Pacific Command, and CENTCOM theaters, cooperating with NATO partners such as United Kingdom, France, and Germany under exercises like DEFENDER-Europe and Operation Atlantic Resolve. Continued transformation is informed by lessons from Operation Iraqi Freedom and Operation Enduring Freedom while preserving regimental heritage through ceremonies, museums, and the archive stewardship of the U.S. Army Center of Military History.

Category:Infantry regiments of the United States Army