American Expeditionary Forces

American Expeditionary Forces
The Institute of Heraldry · Public domain · source
Unit name	American Expeditionary Forces
Caption	AEF staff, 1918
Active	1917–1919
Country	United States
Branch	United States Army
Role	Expeditionary force
Size	~2,000,000
Battles	World War I: Second Battle of the Marne, Battle of Saint-Mihiel, Meuse–Argonne Offensive
Notable commanders	John J. Pershing

Contents

American Expeditionary Forces were the United States military contingents sent to France during World War I under the leadership of General John J. Pershing. Formed after the Zimmermann Telegram and the Lusitania sinking influenced U.S. entry following President Woodrow Wilson’s April 1917 declaration, the AEF grew into a multinational-sized force that participated in major 1918 offensives alongside French Army, British Expeditionary Force, and Belgian Army units. The AEF’s operations affected the final months of World War I and shaped postwar negotiations at the Paris Peace Conference.

Background and Formation

The AEF’s creation followed mobilization policies shaped by Secretary of War Newton D. Baker and Chief of Staff Tasker H. Bliss, influenced by prewar planning from the General Staff and wartime liaison with the French General Staff and British War Office. Recruitment and conscription were enacted under the Selective Service Act of 1917, administered in concert with state National Guard organizations such as the Massachusetts National Guard and New York National Guard. Early deployments included units like the 1st Division (United States), the 27th Division (United States), and the 42nd Infantry Division (Rainbow Division), many of which traced lineage to militia regiments from Boston, New York City, and Chicago. Logistics planning drew on experience from the Spanish–American War and coordination with the United States Shipping Board and U.S. Navy convoys to counter German U-boat threats.

Command authority rested with General John J. Pershing, who resisted amalgamation into British Expeditionary Force or French Army command structures, insisting on independent American formations such as the American II Corps, American V Corps, and corps-level headquarters like I Corps (United States). Divisions included regulars, National Guard, and National Army units, for example 26th Infantry Division (United States), 32nd Infantry Division (United States), and 77th Division (United States). Staff functions interacted with organizations including the Aviation Section, U.S. Signal Corps before the establishment of the United States Army Air Service, the Chemical Warfare Service, the Quartermaster Corps, and the Medical Department (United States Army). Liaison with Allied commands involved figures like Marshal Ferdinand Foch and Generals Joseph Joffre and Sir Douglas Haig.

AEF troops landed at staging areas such as Saint-Nazaire, Brest, France, and Le Havre supporting campaigns including the Second Battle of the Marne, Battle of Saint-Mihiel, and the Meuse–Argonne Offensive. Early engagements saw American units attached to French Army sectors; notable actions involved the Tenth French Army and sectors near Château-Thierry and Belleau Wood, where units like the 2nd Division (United States) fought alongside French formations. Army Air Service squadrons such as 1st Pursuit Group flew from bases including Luxeuil-Saint-Sauveur Air Base and engaged German units including Jagdstaffeln. Naval cooperation with the Royal Navy and Imperial German Navy actions affected convoy escorts and troop transports. Offensive planning integrated with Allied strategy under Compiègne-era coordination and culminated in pushing German forces back across the Hindenburg Line.

Recruitment consisted of drafted and volunteer soldiers drawn from urban centers such as Philadelphia, Cleveland, Los Angeles, and rural regions including Appalachia; distinct units included the 369th Infantry Regiment (Harlem Hellfighters), the 92nd Infantry Division (Buffalo Soldiers), and the 93rd Infantry Division (Colored). Training camps in the United States—Camp Funston, Camp Sherman, Camp Dodge, Camp Lewis, Camp Meade, Camp Upton, and Camp Devens—prepared troops under instructors drawn from the Regular Army and officers commissioned via Officer Training Camps at places like Fort Leavenworth and Fort Benjamin Harrison. Transportation hinged on the United States Shipping Board and merchant fleets like the American Line with port operations at New York Harbor and embarkation points in New Jersey; rail networks including the Pennsylvania Railroad and Baltimore and Ohio Railroad moved men to ports. Supply chains required coordination with the Quartermaster Corps, procurement from companies like Bethlehem Steel, DuPont, and Standard Oil, and logistics innovations in motor transport, railhead organization, and field kitchens.

Battle casualties and disease produced thousands of deaths and wounded treated by the Army Medical Department, Base Hospital No. 1, and units such as the Harvard Unit and Johns Hopkins Unit attached to AEF hospitals in Paris and at evacuation centers in Bordeaux and Brest. Medical advances included triage systems, use of sulfa drugs and earlier antiseptics, and surgical techniques developed by figures like Army surgeons trained at Walter Reed Army Medical Center and affiliated with institutions such as Columbia University and Johns Hopkins University. Casualty statistics were compiled by the Adjutant General's Office and informed public reporting in newspapers including the New York Times and Washington Post. Pandemic influenza of 1918 impacted AEF forces and influenced quarantine measures coordinated with the French Ministry of Public Health.

The AEF’s presence affected the Paris Peace Conference and postwar debates in Washington, D.C. over the Treaty of Versailles and U.S. membership in the League of Nations, shaping careers of leaders like Pershing and politicians including Warren G. Harding and Henry Cabot Lodge. Veterans joined organizations such as the American Legion and the Veterans of Foreign Wars, influencing interwar policy and memorial culture exemplified by monuments in Argonne Forest and cemeteries managed by the American Battle Monuments Commission. The AEF experience influenced development of the United States Army Air Corps, reorganization of the National Guard, and doctrine taught at United States Army War College. Cultural impacts appeared in literature by veterans like Ernest Hemingway and John Dos Passos, and in music and art associated with the Harlem Renaissance and war memorials in New York City and Chicago. The AEF legacy endured in commemorations such as Armistice observances and shaped U.S. military policy into the mid-20th century.