America in WWI

The Call to Arms

President Wilson instituted a draft to catch up to larger European military forces, resulting in the American Expeditionary Force.

Learning Objectives

Analyze America's early role in World War I

Key Takeaways

Key Points

  • The  Selective Service Act  of 1917 authorized the government to raise an army for entry into WWI through a draft that drew them into conscripted military service.
  • Under the Selective Service Act, all males aged 21 to 30 (later expanded to 18 to 45) were required to register for the draft lottery. By the end of the war, 2.8 million men had been drafted.
  • The draft had a high success rate due to the spirit of patriotism during World War I, with fewer than 350,000 men dodging conscription.
  • Unlike in the Civil War draft, men in the 1917 lottery could not legally be hired to take the place of drafted men.

Key Terms

  • Newton D. Baker: (December 3, 1871–December 25, 1937) A Democratic politician who served as the 37th mayor of Cleveland, Ohio, from 1912 to 1915, and as U.S. Secretary of War from 1916 to 1921. Baker recommended the draft to President Woodrow Wilson to

    counter low volunteer rates.
  • John J. Pershing: A general officer in the U.S. Army who led the American Expeditionary Force in World War I. Pershing is the only person to be promoted in his own lifetime to the highest rank ever held in the U.S. Army: general of the armies.
  • General Enoch Crowder: (April 11, 1859–May 7, 1932) Judge advocate general of the U.S. Army from 1911 to 1923, best known for implementing and administering the Selective Service Act, which drafted thousands of American men into military service during World War I.
  • Selective Service Act: Legislation authorizing the federal government to raise a national army through conscription for American entry into World War I. It was envisioned in December 1916, and suggested to President Wilson shortly after the break in relations with Germany in February 1917. The act took effect after the United States declared war on Germany in April 1917, and was canceled with the end of the war in November 1918.

The Selective Service Act, or Selective Draft Act, enacted May 18, 1917, authorized the federal  government to raise a national army through conscription for American entry into World War I. It was envisioned in December 1916, and brought to President Woodrow Wilson shortly after America broke off relations with Germany in February 1917. Captain (later Brigadier General) Hugh Johnson wrote the act after the United States voted to support Wilson’s request for a declaration of war on April 4, 1917. The act was upheld by the U.S. Supreme Court in the Selective Draft Law Cases in 1918, and then canceled with the end of fighting in November 1918.

Origins of the Draft

During the American Civil War, the Draft Act of 1863 was the first law making service in the federal military compulsory for men between the ages of 2o and 45. Yet for $300, a person who was not keen on fighting could pay away the obligation, while draftees also could legally hire substitutes. These were expensive options only open to the wealthy and resulted in a disproportionately low number of rich men fighting in the war, which caused resentment among lower-class citizens and led to the July 1863 draft riots in New York City. When the draft was reinstituted in 1917, this previous conflict was directly addressed by outlawing the practices of draft buyouts or hiring surrogates.

At the outset of World War I in 1914, the U.S. Army was small compared with the mobilized armies of the European powers. The federal army was under 100,000 men, while the National Guard, the organized militias of the states, numbered around 120,000. By 1916, it had become clear that any American participation in the European conflict would require a far larger fighting force. The National Defense Act of 1916 authorized the growth of the army to 165,000 and the National Guard to 450,000 by 1921, but by 1917, the federal army had only expanded to around 121,000, with the National Guard numbering 181,000.

While President Wilson initially wished to use only volunteers, it soon became clear this would not meet the need; three weeks after war was declared, only 97,000 had volunteered for service. Wilson therefore accepted the recommendation from Secretary of War Newton D. Baker to institute a draft. General Enoch Crowder, the U.S. Army’s judge advocate general, indicated his displeasure with the plan. Yet not only did Crowder guide the bill through Congress with the assistance of Captain Hugh Johnson and others, but he also went on to administer the draft in the position of provost marshal general.

Photograph of Enoch Crowder

General Enoch Crowder: Initially opposed to the draft, Crowder took charge of administrating the draft in the post of provost marshal general.

Success of the Draft

Under the Selective Service Act of 1917, all males aged 21 to 30 were required to register for military service. Congress amended the law in August 1918 at the War Department’s request to expand the age range to include all men 18 to 45, and to end further volunteering.

One notable problem that arose in the writing and passage of the bill was former President Theodore Roosevelt’s desire to utilize a wholly volunteer fighting force in Europe, similar to the so-called Rough Riders cavalry regiment in which he served during the Spanish-American War in Cuba. Wilson and others, especially army officers, were reluctant primarily because these men would serve under Roosevelt rather than the established U.S. Army and Navy chain of command, but also because of Roosevelt’s intention to raise one or two regiments of African-American soldiers. The final bill contained a compromise provision permitting the president to raise four separate volunteer divisions, although Wilson neglected to exercise this power.

Approximately 2 million men volunteered to serve in the existing branches of the armed forces, while another 2.8 million were drafted into service by the end of the war, with fewer than 350,000 men "dodging" the draft, likely because of the patriotic fervor that swept the country. The U.S. Congress further supplemented the military by drafting Puerto Ricans as part of the March 1917 Jones-Shafroth Act, which granted U.S. citizenship to, and established a senate and a bill of rights for, residents of Puerto Rico.

The text at the top of the poster readers

"America, Here's My Boy": Sheet music cover for "America Here's My Boy," words by Andrew B. Sterling, music by Arthur Lange. Patriotic fervor is often cited as a reason for the high success rate of the World War I draft.


Draft registration, 1917: This photo shows young men registering for military conscription in New York City, June 5, 1917.

"Associated Power" and the AEF

The United States never formally signed on as a member of the Allies in World War I, but instead nominated itself to be an "associated power" to France and Great Britain in order to avoid "foreign entanglements," which was longstanding American foreign policy. American entry into the war, therefore, was taken up by what became known as the "American Expeditionary Force" (AEF).

A photograph of about thirty uniformed men.

American Expeditionary Force: Officers of the American Expeditionary Force would become crucial to the Allied war effort in Europe by 1918.

In May 1917, President Wilson appointed Major General John J. Pershing as the U.S. armed forces commander. Yet Pershing required that his soldiers were fully trained before going to Europe, resulting in few arriving before 1918. The first American troops, often called "Doughboys," numbered 14,000 in France by June 1917, and grew to a force of more than 1 million by May 1918, half of them on the front lines.

Transport ships needed to bring American troops to Europe were scarce at the beginning, forcing the army to press cruise ships into service, as well as borrowing Allied ships to transport soldiers from New York, New Jersey, and Newport News, Virginia. They also used captured German vessels. 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. French harbors became the entry points into the railway system, which brought U.S. forces and their supplies to the front. American engineers in France built 82 new ship berths, nearly 1,000 miles of additional standard-gauge tracks, and 100,000 miles of telephone and telegraph lines.

Germany miscalculated how quickly the United States could mobilize after its declaration of war, believing many months would pass before the bulk of American soldiers arrived and that their transports could be stopped by the kaiser’s fleet of submersible U-boats. Yet the 1st Division, a formation of experienced regular soldiers and the first combat group to arrive in France, entered the trenches near Nancy in late October 1917.

From 1917–1918, the AEF took part in 13 military campaigns against the Imperial German Army alongside French and British forces. The AEF helped the French Army on the Western Front in June 1918 during the Aisne Offensive at Château-Thierry and Belleau Wood, and later that year fought major actions in the Saint-Mihiel and Meuse-Argonne. Despite the mixed feelings of Allied leaders who distrusted an army lacking experience in large-scale warfare, Pershing insisted that American forces would not be used merely to fill gaps in the French and British armies or act as replacements in decimated Allied units. He made an exception for African-American combat regiments who were used in used in French divisions, notably the Harlem Hellfighters, who earned a Croix de Guerre unit medal for actions with the French 16th Division at Chateau-Thierry, Sechault, and Belleau Wood.


Piave Front, 1918: This photo shows American soldiers on the Piave Front in 1918, hurling hand grenades into the Austrian trenches.

The Western Front

The western front in Europe opened with a German invasion and continued through four years of bloody combat in World War I.

Learning Objectives

Discuss the importance of the Battles of Verdun, Somme, and Passchendaele on the western front

Key Takeaways

Key Points

  • The  German  invasion of Belgium, which resulted in mass civilian casualties, prompted the British to enter the war and mobilized Allied publics around the world.
  • The western front saw the use of new attack methods, including poison gas, aircraft, and tanks, as well as the introduction of airplanes built for combat, which was responsible for mass casualties on both sides.
  • The  Battle of Verdun, the Battle of the Somme, and the Battle of Passchendaele resulted in more than a million casualties on the western front.
  • After the Treaty of Brest-Litovsk, which closed the eastern front, Germans were able to make significant advances during the German Spring Offensive of 1918. Yet the massive casualties sustained along the western front led Germany to sue for peace in 1918.

Key Terms

  • Battle of Verdun: One of the longest and most devastating battles of World War I. Fought on the western front in northeastern France between the German and French armies from February 21 to December 18, 1916, Verdun resulted in a total of 698,000 battlefield deaths: 362,000 French and 336,000 German.
  • German Spring Offensive: A series of attacks beginning on March 21, 1918, in which Germany made its final major advance on the western front as a last ditch attempt at victory before the overwhelming human and material resources of the United States could be deployed. The effort was fueled by the nearly 50 divisions freed by the Russian surrender under the Treaty of Brest-Litovsk.
  • Schlieffen Plan: The German Army strategy, designed by Chief of Staff Alfred von Schlieffen, for quickly overwhelming French forces in the course of an invasion by attacking the French along their shared border and then falling back in the south so that the French would counterattack with reinforcements from the north, allowing the Germans to sweep down and encircle the French Army. The gambit failed when Schlieffen’s replacement as army chief of staff, Helmuth von Moltke, failed to follow its directives, resulting in prolonged trench warfare.

Following the outbreak of World War I in 1914, the German Army opened the western front by invading Luxembourg and Belgium, and then gaining military control of important industrial regions in France. The invasion of Belgium brought in its protector, Great Britain, who fought with the French against Germany and its ally Austria-Hungary along a long line of fortified positions that began a deadly new form of confrontation known as “trench warfare.”

The Western Front Opens

The opening of the western front occurred at the beginning of the conflict in the summer of 1914 when, rather than attack France directly on its smaller shared border, Germany swept to the west through Luxembourg and Belgium and then turned south in order to enter France across its northern border. This was a modified version of a German invasion blueprint known as the " Schlieffen Plan," named for Germany Army Chief of Staff Alfred von Schlieffen, who designed the strategy to quickly overwhelm the French Army.

In its original form, the Schlieffen Plan called for German forces along the French border to attack to the south in areas such as Strasbourg and then pull back in a feigned defeat, causing the French Army to surge south with reinforcement troops and leaving the north weakened. This allowed Germany to push down from the north and make a move to encircle the French forces. This was countered, however, when the new chief of staff, Helmuth von Moltke, diverted from the original plan and attacked in the south rather than fall back. Many historians assert this was due to Moltke’s indecision at the time of the French invasion: He feared a Russian attack in the east but also was enticed by an unplanned chance of victory at Lorraine where he was meant to withdraw.

The initial invasion into France saw the Germans fight the Allies in the Battle of the Frontiers, a series of engagements in eastern France and southern Belgium, until they were nearing the outskirts of Paris. In a counterattack along the Marne River from September 5–12, 1917, which came to be known as the "First Battle of the Marne," or the "Miracle of the Marne," six French combat groups with the help of the British Expeditionary Force pushed the Germans northwest back toward their own border.

This began the so-called "Race to the Sea," a series of battles in which the sides tried to outflank each other in the direction of France’s Atlantic coast. The race resulted in no clear advantage for either the Central Powers or the Allies, who faced off and dug in along a meandering series of fortified trenches that ran up through eastern and northern France into Belgium, a line of “trench warfare” that remained essentially unchanged for most of the war.

Critical and Crippling Battles

Between 1916 and 1917, there were several major offensives in the west. Yet a combination of entrenchments, machine gun nests, barbed wire, and artillery repeatedly inflicted severe casualties on both sides and prevented any significant advances. Among the most costly of these offensives were the Battle of Verdun, the Battle of the Somme, and the Battle of Passchendaele.

The Battle of Verdun began in February 1916. Over the summer and fall, the French slowly advanced and pushed the Germans back in one of the biggest battles of the war that became a symbol of French determination and sacrifice. Yet the price was high, both in numbers and morale. By the end of the Battle of Verdun in December, French casualties are estimated to have reached more than 337,000, including approximately 162,000 dead and missing; total German casualties have been estimated around 337,000, with 100,000 of those dead or missing. The conditions were appalling, with the forests torn apart and the ground churned into a wasteland by artillery fire. Many troops suffered shell shock while others deserted. A French lieutenant, who was later killed, wrote in his diary on May 23, 1916: “Humanity is mad. It must be mad to do what it is doing. What a massacre! What scenes of horror and carnage. I cannot find words to translate my impressions. Hell cannot be so terrible. Men are mad!”

In July 1916, the British launched an attack around the Somme River in France. Despite massive troop losses, the British fought on through November in the face of German reinforcements, but even in the final phase, produced limited gains with heavy loss of life. The Allies suffered about 620,000 casualties in the Battle of the Somme without realizing their goals.

In August 1916, new German leaders along the western front recognized that the battles of Verdun and the Somme had depleted the offensive capabilities of the German Army. They decided to take a defensive posture in the west and created a protective position called the "Hindenburg Line."

In April 1917, French leaders ordered an offensive against the German trenches, promising it would be one to win the war. Dubbed the "Nivelle Offensive," the attacked proceeded poorly and 100,000 French troops fell within a week. The attack continued, and in May, 20,000 French soldiers deserted as morale decreased. Appeals to patriotism and duty, as well as mass arrests and trials resulting in firing squads, eventually convinced troops to return to defend their trenches, although the soldiers refused to participate in further offensive action.

Beginning on July 31 and continuing to November 10, 1917, an ongoing struggle around Ypres was renewed with the Battle of Passchendaele, officially known as the "Third Battle of Ypres"; the First Ypres took place from October to November 1914 and the Second Ypres from April to May 1915. The final result of the third offensive, marked by British and Canadian forces taking the village of Passchendaele, was approximately five miles of territory gained with the loss of more than a half million men on both sides.

The tide of the German advance into France was finally, dramatically turned with the Second Battle of the Marne from July 15 to August 6, 1918. This would be the last German offensive of the war.


"At Close Grips": Two U.S. soldiers run past the remains of two German soldiers toward a bunker. Trench warfare characterized the western front of World War I.

Arms Race

As troops strove to break the deadlock, the western front saw the introduction of new military technology, such as chemical weapons. Airplanes had already been used in the war for scouting, and in 1915, a French pilot shot down an enemy plane. This started a back-and-forth arms race, as both sides developed improved aircraft capabilities. Tanks also were used extensively for the first time following the Somme, which led directly to new developments in infantry organization including small tactical units.

Final Phases and Armistice

On March 3, 1918, the Treaty of Brest-Litovsk was signed with Russia, allowing German and Austro Hungarian troops to move from the eastern front to the fighting in the west. Yet a rapidly increasing American presence, eventually totaling 2.1 million U.S. soldiers on the western front, effectively countered the redeployed Germans. With its economy and society under great strain, Germany finally broke under the Allied series of attacks known as "The Hundred Days Offensive" beginning in August 1918. The combatants signed a ceasefire, and all fighting on the western front ended on November 11, 1918, which became known as "Armistice Day."

The War in France

The American Expeditionary Forces (AEF) served alongside the French and British armies on the western front.

Learning Objectives

Summarize the role and battle approach of the American Expeditionary Forces (AEF) in France

Key Takeaways

Key Points

  • General John Pershing, appointed by President Wilson to command the American Expeditionary Forces (AEF), insisted that American forces be well-trained before going to Europe.
  • Through engagements in France, the AEF developed into a modern combat army. American troops played a key role in preventing the Germans from advancing toward Paris in the Second Battle of the Marne in June 1918. In the Battle of Hamel on July 4, U.S. forces successfully employed a "combined arms" approach using artillery, armor, infantry, and air support.
  • African-American males were drafted into the AEF on the same basis as whites and served on the western front in segregated units commanded by white officers, although they saw less combat and were often restricted to unskilled labor tasks.
  • The AEF sustained approximately 320,000 casualties and 204,000 wounded.

Key Terms

  • American Expeditionary Forces (AEF): The American Expeditionary Forces, or AEF, were the U.S. troops sent to Europe in World War I. The AEF fought in France alongside French and British forces in the last year of the war against Germany.
  • General John Joseph "Black Jack" Pershing: The commander of the American Expeditionary Forces in World War I. He is the only person to have been promoted to the highest rank ever held in the U.S. Army, general of the armies, in his own lifetime.
  • Harlem Hellfighters: The U.S. Army’s 369th Infantry Regiment, formerly the 15th New York National Guard Regiment, known for being the first African-American regiment to serve with the American Expeditionary Forces during World War I. The regiment was called the "Harlem Hellfighters" and the "Black Rattlers," in addition to several other admiring nicknames during its service in both world wars.

The American Expeditionary Forces

The American Expeditionary Forces (AEF) were the U.S. troops, often called “Doughboys,” sent to fight in France alongside the British and French armies against Germany under the command of Major General John Joseph "Black Jack" Pershing. The overall goal of the AEF was to reinforce the ongoing campaign against Germany by the French and British and bring the war to a victorious conclusion for the Allies.

Before the AEF

Between 1915 and 1917, before the beginning of major American involvement in the war, there were several offensives along the western front by the Allied forces of Britain and France and the invading German forces intent on throwing each other backward until a sufficient amount of ground could be gained to claim victory.

Following the Race to the Sea, a series of battles aimed at flanking the enemy up to the Atlantic coast, and the decisive Battle of the Marne that stopped the German advance into France, the front line was established near the French and German border from the Swiss frontier to Belgium. The warring sides tried continuously to break the stalemate using a combination of massive artillery barrages, machine gun nests, snipers, poison gas, and aircraft attacks. The Battle of Verdun in 1916 produced an estimated 700,000 casualties from both sides, while the Battle of the Somme in that same year and the Battle of Passchendaele in 1917 ended with a combined death total of more than 1.6 million men. These battles were marked by destructive attacks and counter-assaults by foot soldiers launched from opposing trenches.

Trench Warfare

Trench warfare epitomized the long, bloody conflict between the opposing armies on the western front, and has since become a term used when describing a futile battle marked by attrition—huge losses that achieve only negligible results.

The trenches were networks of defensive, fortified positions connected by sunken channels of varying lengths and quality. Some trenches were long, complicated systems that were dug deeply—from 8 to 12 feet below the surface—and sturdily reinforced with wooden supports, shielding troops from artillery and small-arms fire. Others were no more than dugouts that resembled large gutters along the frontlines. They were joined in zig-zagging or stepped patterns that prevented a soldier from seeing down one trench more than about 10 meters (11 yards) and thus sectioned off in order to prevent an entire trench from being captured if it were infiltrated at one point. The top lip of the trench was known as the "parapet," and soldiers stood on steps below with hand-held periscopes—which sometimes amounted to as simple a tool as angled mirrors at the top and bottom of a stick—that enabled them to look out toward the enemy without being exposed.


French 87th Regiment Cote 34 Verdun, 1916: This photo shows French soldiers of the 87th Regiment, 6th Division, at Côte 304 (Hill 304), in trenches northwest of Verdun, 1916.

The wet weather of the French countryside often turned the ground, already dug up by shelling, into fields of thick mud. Inside the trenches, the rain and muck could fill up the winding fortifications to the point that soldiers became trapped, and some even drowned or suffocated under crumbling earthen walls. The armies faced off in their respective trenches with open areas of varying widths between them. These areas, called “no man’s land,” were fully exposed to enemy fire and shelling and often were crossed with long fences of barbed wire to slow the charges that soldiers were forced to make, resulting in enormous casualties regardless of their success.

The trenches of World War I produced far more horrors than quantifiable victories, and the production of tanks, which were put into regular use in the latter part of the conflict, was a direct result of military leaders coming to the conclusion that trench warfare was an untenable strategy.

AEF Battles in France

During early 1918, 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 at the Battle of Cantigny on May 28 and another at Belleau Wood beginning June 6, Pershing worked to deploy a full field army. By June 1918, Americans arrived in the theater at a rate of

10,000 per day.

The first AEF offensive action with British forces was conducted by 1,000 men serving with the Australian Imperial Forces during the Battle of Hamel on July 4, 1918. Combining artillery, armor, infantry, and air support, the battle was a blueprint for subsequent Allied tank attacks. American Army and Marine Corps troops later played a key role in stopping the German thrust toward Paris during the Second Battle of the Marne in June 1918.

The first distinctly American offensive was the Battle of Saint-Mihiel, beginning September 12, 1918. Pershing commanded more than 500,000 men in the largest offensive operation ever undertaken by U.S. forces to date. This success was followed by the Meuse-Argonne offensive from September 26 to November 11, 1918, in which Pershing commanded more than 1 million American and French troops. In these two military operations, Allied forces recovered more than 200 square miles of French territory from the Germans.

Overall the AEF sustained about 320,000 casualties and 204,000 wounded. The Fall 1918 influenza pandemic took the lives of more than 25,000 men, while another 360,000 became gravely ill. Other diseases were relatively well-controlled through compulsory vaccination.

By the time an armistice ended all fighting on November 11, 1918, the AEF had evolved into a modern, combat-tested army. Based on their success, European powers late in the war requested the aid of American units in Italy, as well as in Russia, where they were known as the "American Expeditionary Force Siberia" and the "American Expeditionary Force North Russia."


World War I field hospital: This photo shows an American army field hospital inside ruins of a church (France 1918). The AEF sustained more than 300,000 casualties.

African Americans in the AEF

African Americans were drafted on the same basis as whites and made up 13% of draftees. By the end of the war, more than 350,000 African Americans served in AEF units on the western front, although they were assigned to segregated units commanded by white officers under a policy approved by President Wilson.

The French, whose frontline troops at times resisted combat duties to the point of mutiny, requested and received control of several regiments of black American combat troops. The French did not display the same levels of disdain based on skin color as the American Army and for many African Americans, being directed by the French was a far more tolerable experience. The 370th, 371st, and 372nd Infantry Regiments served with distinction, while the 369th regiment became admiringly known as the "Harlem Hellfighters."

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