American Expeditionary Forces The American Expeditionary Forces ( AEF ) were the United States Armed Forces sent to Europe in World War I . During the United States campaigns in World War I the AEF fought in France alongside French and British allied forces in the last year of the war , against Imperial German forces . The AEF helped the French Army on the Western Front during the Aisne Offensive ( at Château - Thierry and Belleau Wood ) in June 1918 , and fought its major actions in the Saint - Mihiel and Meuse - Argonne Offensive s in late 1918 . Overview . President Woodrow Wilson initially planned to give command of the AEF to General Frederick Funston , but after Funston ' s sudden death , Wilson appointed Major General John J . " Jack " Pershing in May 1917 ; Pershing remained in command for the entire war . Pershing insisted that American soldiers be well - trained before going to Europe . As a result , few troops arrived before 1918 . In addition , Pershing insisted that the American force would not be used merely to fill gaps in the French and British armies , and he resisted European efforts to have U . S . troops deployed as individual replacements in decimated Allied units . This attitude was not always well received by the Allied leaders who distrusted the potential of an army lacking experience in large - scale warfare . In addition the British tried to barter their spare shipping to make the US put its soldiers into British ranks . By June 1917 , 14 , 000 U . S . soldiers had already arrived in France , and by May 1918 over one million U . S . troops were stationed in France , half of them being on the front lines . Since the transport ships needed to bring American troops to Europe were scarce at the beginning , the army pressed into service cruise ships , seized German ships , and borrowed Allied ships to transport American soldiers from New York , New Jersey , and Newport News , Virginia . The mobilization effort taxed the American military to the limit and required new organizational strategies and command structures to transport great numbers of troops and supplies quickly and efficiently . The French harbors of Bordeaux , La Pallice , Saint Nazaire and Brest became the entry points into the French railway system which brought the US forces and their supplies to the front . American engineers in France built 82 new ship berths , nearly of additional standard - gauge tracks and of telephone and telegraph lines . The first American troops , who were often called " Doughboy s " , landed in Europe in June 1917 . However the AEF did not participate at the front until late October 1917 , when the 1st Division , a formation of experienced regular soldiers and the first division to arrive in France , entered the trenches near Nancy . The AEF used French and British equipment . Particularly appreciated were the French canon de 75 , the canon de 155 C modele 1917 Schneider and the canon de 155mm GPF . American aviation units received the SPAD XIII and Nieuport 28 fighters and the US tank corps used the French Renault FT light tanks . Pershing established facilities in France to train new arrivals with their new weapons . By the end of 1917 four divisions were deployed in a large training area near Verdun : the 1st Division , a regular army formation ; the 26th Division , a National Guard formation ; the 2nd Division , a combined formation of regular troops and United States Marines ; and the 42nd " Rainbow " Division , a National Guard formation consisting of units from nearly every state in the United States . A fifth division , the 41st Division , had been converted into a depot division near Tours . At the beginning , during early 1918 , the four battle - ready U . S . divisions were deployed with French and British units to gain combat experience by defending relatively quiet sectors of their lines . After the first offensive action and AEF victory on 28 May 1918 at the Battle of Cantigny , by the 1st U . S . Division , and a similar local action by the 2nd Division at Belleau Wood beginning 6 June , both while assigned to French armies , Pershing worked towards the deployment of a US field Army . The rest followed at an accelerating pace during the spring and summer of 1918 . By June Americans were arriving in - theatre at the rate of 10 , 000 a day . The first offensive action undertaken by AEF units serving with British forces ( Corporal Thomas A . Pope was awarded the Medal of Honor for this battle ) was by 1 , 000 men ( 4 Companies from the 33rd Division AEF ) serving with the Australian Imperial Force ( AIF ) during the Battle of Hamel on 4 July 1918 . This battle took place under the overall command of Australian Corps Commander Lt . General Sir John Monash and combined Artillery , Armour , Infantry and Air Support ( Combined Arms ) , serving as a blueprint for all subsequent Allied attacks using " Tanks " . American Army and Marine Corps troops played a key role in helping stop the German thrust towards Paris , during the Second Battle of the Marne in June 1918 ( at Château - Thierry and Belleau Wood ) . The first major and distinctly American offensive was the reduction of the Saint Mihiel salient in September 1918 . During the Battle of Saint - Mihiel , beginning September 12 , 1918 , Pershing commanded the American First Army , comprising seven division s and more than 500 , 000 men , in the largest offensive operation ever undertaken by United States armed forces to date . This successful offensive was followed by the Meuse - Argonne offensive , lasting from September 26 to November 11 , 1918 , during which General Pershing commanded more than one million American and French combatants . In these two military operations , Allied forces recovered more than 200sqmi ( 488sqkm ) of French territory from the German army . By the time the Armistice had suspended all combat on November 11 , 1918 , the American Expeditionary Forces had evolved into a modern , combat - tested army . Late in the war American units ultimately fought in two other theaters at the request of European powers ; Pershing sent troops of the 332nd Infantry to Italy , and President Wilson agreed to send troops , the 27th and 339th Infantry Regiments , to Russia ; these latter two were known as the American Expeditionary Force Siberia , and the American Expeditionary Force North Russia . Casualties . The AEF sustained about 320 , 000 casualties ; 53 , 402 battle deaths , 63 , 114 non combat deaths and 204 , 000 wounded . This high AEF casualty count was sustained at a time when French casualties for 1918 are listed as 330 , 000 , but with a much longer front line to hold . The influenza pandemic during the fall of 1918 took the lives of more than 25 , 000 men from the AEF while another 360 , 000 became gravely ill . Other diseases were relatively well controlled through compulsory vaccination . Typhoid fever was also practically eliminated . Relatively few men suffered actual injury from poison gas , although much larger numbers mistakenly thought that they had been exposed . African Americans . African Americans were drafted on the same basis as whites and made up 13 % of the draftees . By the end of the war , over 350 , 000 African - Americans had served in AEF units on the Western Front . However , they were assigned to segregated units commanded by white officers . One fifth of the black soldiers sent to France saw combat , compared to two - thirds of the whites . " The mass of the colored drafted men cannot be used for combatant troops " , said a General Staff report in 1918 , and it recommended that " these colored drafted men be organized in reserve labor battalions . " They handled unskilled labor tasks as stevedores in the Atlantic ports and common laborers at the camps and in the Services of the Rear in France . The French , whose front - line troops were resisting combat duties to the point of mutiny , requested and received control of several regiments of black combat troops . Kennedy reports : The 369th , 370th , 371st , and 372nd Infantry Regiments served with distinction under French command with French colonial units in front - line combat . The French did not harbor the same levels of disdain based on skin color and for many Americans of an African - American descent it was a liberating and refreshing experience . These African - American soldiers wore American uniforms , some dating from the time of the Union Army , with French helmets and were armed with French Model 1907 / 15 8mm Lebel Berthier rifles manufactured by Remington Arms rather than M1903 Springfield or M1917 Enfield rifles issued to most American soldiers . One of the most distinguished units was the 369th Infantry Regiment , known as the Harlem Hellfighters . The 369th was on the front lines for six months , longer than any other African - American regiment in the war . One hundred seventy - one members of the 369th were awarded the Legion of Merit . . One member of the 369th , Sgt . Henry Lincoln Johnson , was awarded the French Croix de guerre , and has been considered for a posthumous Medal of Honor .