When the guns of August 1914 shattered the peace of Europe, pitting Germany and Austria-Hungary (the Central Powers) against Britain, France, and Russia, President Woodrow Wilson on August 4 issued a proclamation of neutrality. Two weeks later he urged Americans to be "impartial in thought as well as in action." But in the realms of both official policy and public opinion, neutrality proved difficult to sustain. Wilson insisted, for reasons of both principle and economic advantage, on full neutral trading rights with all the belligerent powers. Britain and Germany had different ideas. Each tried to throttle American trade with the other. Britain, whose battle fleet controlled the surface of the Atlantic, succeeded spectacularly. American commerce with Germany had fallen by 1916 to less than 1 percent of its 1914 value. In the same period, American trade with Britain and its French and (after 1915) Italian allies tripled.
British restrictions on American trade elicited repeated American complaints, but the harm done by British commercial regulations and surface ships paled next to the damage inflicted by German submarines. The U-boat (Unterseeboot) ignored existing rules of naval warfare. Contrary to the traditional practice, submerged U-boats torpedoed merchant ships without warning. When sinkings resulted in the loss of American lives - as in the assault on the British passenger liner Lusitania on May 7, 1915, killing 128 Americans - Wilson's government protested vehemently. Germany restrained its submarine attacks thereafter, but on January 31, 1917, in a desperate move to end the two-and-a-half-year-old military stalemate in Europe, the German high command declared unrestricted submarine warfare against all shipping, neutral or belligerent, destined for Britain.
Wilson broke diplomatic relations with Berlin, but declined to ask Congress for a declaration of war in the absence of "actual overt acts" against American lives and property. He sought instead to arm American merchant vessels as a way of forestalling attacks and thus avoiding war. But the "overt acts" came with the sinking of several American ships in February and March 1917. At about the same time, newspapers published an intercepted telegram from German foreign minister Arthur Zimmermann, proposing a German-Mexican alliance against the United States. Mexico's reward would be the recovery of territory it had lost in Texas, New Mexico, and Arizona. Wilson, though reelected in November 1916 on the slogan "He kept us out of war," asked Congress on April 2 for a declaration of war. Four days later, Congress complied, with six senators and fifty representatives (including the first congresswoman, Jeannette Rankin of Montana) voting against the war resolution.
"It is a fearful thing to lead this great peaceful people into war," Wilson declared in his war message. It was fearful indeed. The war had already butchered millions of Europeans and shredded the social fabric of many of the belligerent states, and in the United States, many people still opposed America's involvement in the conflict.
Many factors fostered the American reservations, even after the U-boat attacks and the Zimmermann telegram. One was Wilson's own suspicions about the war aims of Britain and France, which precluded his becoming their formal ally. At his insistence, the United States officially fought as an "Associated Power." Others included America's historical isolation from European embroilments; the geographical remoteness of the fighting; the tangled and confusing causes of the war in noxious European imperial rivalries; the partisan contentiousness of the era of progressive reform over which Wilson and his predecessor, Theodore Roosevelt, had presided; and, above all, the deep ethnic divisions in early twentieth-century American society. The 1910 census revealed that one out of every three Americans was either foreign-born or the child of a foreign-born parent. Of those 32 million Americans with strong foreign ties, some 10 million came from what were now the enemy countries of Germany and Austria-Hungary. Neither their loyalty to the American cause nor even the enthusiasm for the war of millions of other Americans could be taken for granted.
Knowing this, the Wilson administration undertook an extraordinary propaganda campaign aimed at shaping American public opinion favorable to the war and mobilization efforts. The centerpiece of this campaign was the Committee on Public Information cpi, formed in April 1917 and headed by progressive journalist George Creel. The cpi mobilized some seventy-five thousand speakers - "four-minute men" - who delivered patriotic exhortations in churches, schools, movie houses, and other public places. It distributed 75 million copies of pamphlets in several languages explaining America's relation to the war. It sponsored war expositions in nearly two dozen cities and produced films like The Kaiser: The Beast of Berlin.
Other government agencies, such as the Food Administration under Herbert Hoover and the Treasury under William Gibbs McAdoo, employed similar techniques. Hoover exhorted housewives in the name of patriotism to observe "meatless Mondays" and "wheatless Wednesdays" as food conservation measures. McAdoo sponsored gigantic rallies to urge the purchase of war bonds. These approaches typified the American mobilization effort, which relied less on the majesty of the law (food rationing or heavy taxation, for example) and more on aroused passion and voluntary compliance to accomplish its goals. Even the War Industries Board, usually considered the most potent of the wartime mobilization agencies, exercised its actually modest powers with reluctance. Its colorful chairman, lone-eagle stock speculator Bernard M. Baruch, doubted the statutory basis for many of the actions he wanted to take to orchestrate American industrial production. Accordingly, he relied instead on suasion, cajolery, and occasionally the threat of public humiliation to work his will. Even in the midst of a globe-girdling crisis, Americans thus expressed their historic preference for the principles of laissez-faire and their fear of a strong central government.
The crisis of war nevertheless pressed in with sufficient urgency that the Wilson administration had eventually to resort to the blunt exercise of governmental power, as when it took over the operation of the nation's railroads in late 1917. But in general, the government applied less naked force to the economy than it did to the suppression of dissenting political opinion. The Espionage Act of June 15, 1917, as amended by the so-called Sedition Act of May 16, 1918, provided the legal foundation for sundry prosecutions of pacifists and left-wing political groups opposed to the war, such as the Socialists and the Industrial Workers of the World iww. In the controversial case of Schenck v. United States in 1919, the Supreme Court upheld the constitutionality of the Espionage Act. Government propaganda also fueled the fires of popular passion and helped create an atmosphere in which an aroused vigilantism led to numerous atrocities. Especially victimized by these emotional outbursts were German-Americans. Though they had historically been among the most esteemed immigrant groups, they now found themselves the targets of a mindless fury that knew few restraints. Familiar German terms like "hamburger" and "sauerkraut" were replaced by "liberty sandwich" and "liberty cabbage." Playing German music and teaching - or even speaking - the German language were prohibited. One German-American was stripped, bound with an American flag, and lynched by a mob of five hundred persons near St. Louis.
The Selective Service Act of May 18, 1917, helped raise the size of the American army from about 200,000 men in early 1917 to nearly 4 million by war's end. Some 2 million men served overseas in the American Expeditionary Force aef, of whom roughly three-quarters experienced combat. Gen. John J. Pershing, commander of the aef landed in France on June 14, 1917, and his troops began to arrive the following month. They came slowly at first and then in greatly accelerating numbers in the spring and summer of 1918.
As men left for the fighting front, employment opportunities opened up for women. Some prominent women like Jane Addams opposed American entrance into the war on pacifist grounds. But many other women leaders welcomed the chance, as a Women's Trade Union League speaker put it in 1917, to come "into the labor and festival of life on equal terms with men." About a million women entered the labor force during the war, but most quickly departed when peace returned.
Russia, under a new revolutionary government, concluded a separate peace with Germany and left the war in March 1918. (Wilson's famous Fourteen Points, announced on January 8, 1918, as the basis for a nonpunitive peace settlement with Germany, were prompted in part by an effort to keep reeling Russia in the war. But the effort was in vain.) The Germans thereupon began shifting troops from the Russian to the western front, preparatory to the mounting of a massive offensive on March 21, 1918. British and French officials now redoubled their demands that American troops be amalgamated into Allied units. All such requests Pershing, under orders to make the aef a "distinct and separate component," had adamantly denied. Now he partially relented and allowed American soldiers and marines to be thrown in under foreign command to brace the buckling Allied lines. Green American troops fought at Cantigny in May 1918 and at Chateau-Thierry and Belleau Wood in June. The German drive was halted. The American giant had arisen in the West, Winston Churchill later wrote, to replace the dying Russian titan in the East.
On August 10 the First U.S. Army was formed and assigned to a sector of the front stretching from the area around Verdun eastward to the Vosges Mountains. The American role in the counteroffensive of 1918 was twofold: to reduce the German salient behind the village of Saint-Mihiel to the southeast of Verdun, and then to attack the main German front to the northwest of Verdun, through the heavily fortified terrain bounded by the Meuse River on the west and the Argonne Forest on the east. The ultimate American objective was the important German railroad center at Sedan.
The Saint-Mihiel campaign, September 12-16, 1918, went smoothly, largely because the American attack happened to catch the Germans in the midst of a previously planned evacuation. The Meuse-Argonne offensive, launched on September 26, 1918, was a different matter. The Germans were deeply entrenched in formidable defenses. The terrain exposed the attackers to murderous enfilade as they proceeded up the two narrow valleys that flanked the first American objective, the strategic heights of Monfaucon. But the Americans had the advantage of numbers. Pershing hurled some 1.2 million "doughboys" into the Meuse-Argonne attack, and though their inexperience produced appalling casualties, their sheer quantity finally broke the German resistance. Germany quickly realized it could not hold out against the western Allies now that the huge weight of America's apparently inexhaustible manpower reserves had been thrown into the scales. Germany had initiated unrestricted submarine warfare on the calculated gamble that this would bring the Allies to their knees before the United States could field an effective fighting force. Germany lost that gamble, and the war ended with the surrender of the Central Powers on November 11, 1918. Total American war deaths were 112,432, more than half from disease. Government expenditures related to the war totaled some $26 billion during wartime, and eventually, with interest rates, veterans' benefits, and the like, the war's direct financial cost to the United States came to about $112.
America's main contributions to the victory over the Central Powers had been foodstuffs, manpower, and money. The Allies depended neither on American armaments nor, in the last analysis, on American military victories in the field. They had sufficient weapons of their own and in fact supplied most munitions of war to the aef which sailed in British ships, fired British and French artillery, and flew Allied aircraft. But without American food and especially financial resources - some $10 billion in U.S. Treasury loans were extended to the Allied governments in the two years after April 1917 - Britain, France, and Italy would probably have had to sue for terms. Similarly, it was not so much American fighting prowess as the prospect of endless American reinforcements that tipped the scales against Germany in late 1918.
At home, the war had been too brief to have had a deeply transformative effect on American society. In this respect it differed from the Civil War as well as World War II. But the war did plant the seeds and provide the models for much future change. Wartime labor shortages, for example, drew hundreds of thousands of African-Americans out of the South and into industrial employment in the North, laying the foundations for large black communities in cities like Chicago and New York. The mass movement of African-Americans into what had been predominantly white communities provoked interracial friction and occasionally violence. Vicious race riots broke out in East St. Louis in July 1917, killing nine whites and a larger but undetermined number of blacks. Even worse rioting rocked Chicago in July 1919, leaving fifteen whites and twenty-three blacks dead. Blacks also served in the military, under conditions that reflected the segregationist practices common to American society at the time. They were brigaded in all-black units under white officers and mostly assigned noncombat roles in construction battalions and as stevedores. Four regiments of the Ninety-third Division were seconded to the French army and fought well enough to receive unit citations for bravery. Yet the poor record of the Ninety-second Division's 368th Regiment in the Meuse-Argonne offensive received more attention in the press and seemed to confirm racist opinions that blacks were unsuited for combat.
The war established many precedents for future political developments. The War Finance Corporation, established to help firms convert to military production, inspired the Hoover administration's chief antidepression tool, the Reconstruction Finance Corporation. The New Deal's National Recovery Administration was patterned on the War Industries Board. The National War Labor Board, charged with mediating wartime labor disputes, provided an important precedent for the Wagner National Labor Relations Act of 1935. And there were the more immediate and concrete achievements, at least partly facilitated by the war, of Prohibition, which was enacted by the Eighteenth Amendment in 1919, and women's suffrage, guaranteed by the Nineteenth Amendment in 1920. The war also introduced sufficient stresses into American society that Woodrow Wilson's Democratic party, despite its military victory, lost control of the Congress in 1918 and of the presidency in 1920, ushering in a decade of Republican dominance in national politics.