The United States became directly involved in World War I after declaring war with Germany on April 6, 1917. The declaration ended nearly three years of American neutrality in the war since its beginning, and the country's involvement in the conflict lasted over nineteen months before a ceasefire and armistice were declared on November 11, 1918. The U.S. played a major role in providing much needed supplies, raw material, and money to the United Kingdom, France, and the other Allied powers, even well before 1917.
After declaring war, the U.S. mobilized over 5 million military personnel. General John J. Pershing commanded the American Expeditionary Force (AEF) in France, in which over 2 million American soldiers served. American troops began to arrive in Europe by June 1917, first at a slow rate, but by the summer of 1918 the rate had skyrocketed to 10,000 soldiers arriving each day. Most of the ground fighting for the U.S. took place on the Western Front. At sea, the U.S. Navy would play a key role in the Allied convoy system and in the ongoing battle against German submarines. Over 116,000 American servicemen were lost in the war.
Although there was an initially slow start in mobilizing the armed forces, economy and labor force, by spring 1918, the nation was poised to play a decisive role in the conflict. Under the leadership of President Woodrow Wilson, the war saw a dramatic expansion of the United States government in an attempt to harness the war effort and to significantly increase in the size of the U.S. Armed Forces. The war also represented the climax of the Progressive Era, as it sought to bring reform and democracy to the world.
Beginning
The First World War began on July 28, 1914, and United States officially entered the war with a declaration of war on the German Empire on April 6, 1917. Though there was a small amount of Anglophile citizens vocalizing support for the United States to enter the war early, support for neutrality in the conflict was strong among Irish, German, and Scandinavian Americans, as well as among members of Christian clergy and women in general. Despite this, the general opinion among US citizens of Germany was incredibly poor, worse than their opinion of any other European country.Barnes, Harry Elmer. The Genesis of the World War (1925) pp. 590–591 Over time, especially after reports of German atrocities in Belgium in 1914 and following the sinking of the passenger liner RMS Lusitania in 1915, the American people increasingly came to see the German Empire as the aggressor.
Sitting US president Woodrow Wilson made the key policy decisions over foreign affairs: while the country was at peace, the domestic economy ran on a laissez-faire basis, with American banks making huge loans to Britain and France — funds that were in large part used to buy munitions, raw materials, and food from across the Atlantic. Until 1917, Wilson made minimal preparations for a land war and kept the United States Army on a small peacetime footing, despite increasing demands for enhanced preparedness. He did, however, expand the United States Navy.
In 1917, with the Russian Revolution and widespread disillusionment over the war, and with Britain and France low on credit, the German Empire appeared to have the upper hand in Europe, while the Ottoman Empire clung to its possessions in the Middle East. In the same year, the German Empire decided to resume unrestricted submarine warfare against any vessel approaching British waters; this attempt to starve Britain into surrender was balanced against the knowledge that it would almost certainly bring the United States into the war. The German Empire also made a secret offer to help Mexico regain territories lost in the Mexican–American War in an encoded telegram known as the Zimmermann telegram, which was intercepted by British intelligence. Publication of that communique outraged Americans just as German U-boats started sinking American merchant ships in the North Atlantic. Wilson then asked Congress for "a war to end all wars" that would "make the world safe for democracy", and Congress voted to declare war on the German Empire on April 6, 1917. On December 7, 1917, the U.S. declared war on Austria-Hungary.H.J.Res.169: Declaration of War with Austria-Hungary, WWI , United States Senate
Neutrality
After the war began in 1914, the United States and Japan were the only uninvolved Great Powers. The United States remained neutral at the beginning of the conflict, despite president Woodrow Wilson's vocal dislikes of the warmonger tendencies of the German Empire.
When the German U-boat U-20 sank the British liner on 7 May 1915 with 128 U.S. citizens aboard, Wilson demanded an end to German attacks on passenger ships, and warned that the US would not tolerate unrestricted submarine warfare in violation of "American rights" and of "international obligations." Wilson's Secretary of State, William Jennings Bryan, resigned, believing that the President's protests against the German use of U-boat attacks conflicted with America's official commitment to neutrality. On the other hand, Wilson came under pressure from war hawks led by former president Theodore Roosevelt, who denounced German acts as "piracy",H.W. Brands, T.R.: The Last Romantic (1997) p=756 and from British delegations under Cecil Spring Rice and Sir Edward Grey.
The American public reacted with outrage to the suspected German sabotage of Black Tom in Jersey City, New Jersey on 30 July 1916, and to the Kingsland explosion on 11 January 1917 in present-day Lyndhurst, New Jersey.Jules Witcover, Black Tom: Imperial Germany's Secret War in America (1989). Also in January 1917, the Zimmerman Telegram, through which the German government sought to enlist Mexico as an ally and instigate a Mexican invasion of the U.S., was leaked, further inflaming anti-German sentiment.
Crucially, by the spring of 1917, President Wilson's official commitment to neutrality had finally unraveled. Wilson realized he needed to enter the war in order to shape the peace and implement his vision for a League of Nations at the Paris Peace Conference.
Public opinion
American public opinion was divided, with most Americans until early 1917 largely of the opinion that the United States should stay out of the war. Opinion changed gradually, partly in response to German actions in Belgium and the Lusitania, partly as German Americans lost influence, and partly in response to Wilson's position that America had to play a role to make the world safe for democracy.Ernest R. May, The World War and American Isolation, 1914-1917 (1959)
In the general public, there was little if any support for entering the war on the side of the Central Powers. The great majority of German Americans, as well as Scandinavian Americans, wanted the United States to remain neutral; however, at the outbreak of war, thousands of U.S. citizens had tried to enlist in the German army.Hew Strachan, The First World War (2003)TV Series, The First World War Part 7: Blockade (2003) The Irish Catholic community, based in the large cities and often in control of the Democratic Party apparatus, was strongly hostile to helping Britain in any way, especially after the Easter Rising of 1916 in Ireland.William M. Leary, Jr., "Woodrow Wilson, Irish Americans, and the Election of 1916," Journal of American History Vol. 54, No. 1 (Jun. 1967), pp. 57-72 Most of the Protestant church leaders in the United States, regardless of their theology, favored pacifistic solutions whereby the United States would broker a peace.Patricia Appelbaum, Kingdom to Commune: Protestant Pacifist Culture between World War I and the Vietnam Era (2009) Most of the leaders of the women's movement, typified by Jane Addams, likewise sought pacifistic solutions.Frances H. Early, A World without War: How U.S. Feminists and Pacifists Resisted World War I (1997) The most prominent opponent of war was industrialist Henry Ford, who personally financed and led a peace ship to Europe to try to negotiate among the belligerents; no negotiations resulted.Barbara S. Kraft, The peace ship: Henry Ford's pacifist adventure in the First World War (1978)
Britain had significant support among intellectuals and families with close ties to Britain.H. C. Peterson, Propaganda for War: The Campaign Against American Neutrality, 1914-1917 (1968) The most prominent leader was Samuel Insull of Chicago, a leading industrialist who had emigrated from England. Insull funded many propaganda efforts, and financed young Americans who wished to fight by joining the Canadian military.Forrest McDonald, Insull: The Rise and Fall of a Billionaire Utility Tycoon (2004)"Constitution Act, 1867". Her Majesty the Queen in Right of Canada. March 29, 1867. p. s.9. Retrieved September 3, 2012.
Preparedness movement
By 1915, Americans were paying much more attention to the war. The sinking of the Lusitania aroused furious denunciations of German brutality.Frank Trommler, "The Lusitania Effect: America's Mobilization against Germany in World War I" German Studies Review 32#2 (2009), pp. 241-266 online In Eastern cities a new "Preparedness" movement emerged. It argued that the United States needed to build up immediately strong naval and land forces for defensive purposes; an unspoken assumption was that America would fight sooner or later. The driving forces behind Preparedness were all Republicans, notably General Leonard Wood, ex-president Theodore Roosevelt, and former secretaries of war Elihu Root and Henry Stimson; they enlisted many of the nation's most prominent bankers, industrialists, lawyers and scions of prominent families. Indeed, there emerged an "Atlanticist" foreign policy establishment, a group of influential Americans drawn primarily from upper-class lawyers, bankers, academics, and politicians of the Northeast, committed to a strand of Anglophile internationalism.Priscilla Roberts, "Paul D. Cravath, the First World War, and the Anglophile Internationalist Tradition." Australian Journal of Politics and History 2005 51(2): 194-215.
The Preparedness movement had what political scientists call a "realism" philosophy of world affairs—they believed that economic strength and military muscle were more decisive than idealistic crusades focused on causes like democracy and national self-determination. Emphasizing over and over the weak state of national defenses, they showed that the United States' 100,000-man Army, even augmented by the 112,000-strong National Guard, was outnumbered 20 to one by the German army; similarly in 1915, the armed forces of Great Britain and the British Empire, France, Russia, the Austro-Hungarian Empire, Ottoman Empire, Italy, Bulgaria, Romania, Serbia, Belgium, Japan, and Greece were all larger and more experienced than the United States military.
They called for UMT or "universal military service" under which the 600,000 men who turned 18 every year would be required to spend six months in military training, and then be assigned to reserve units. The small regular army would primarily be a training agency. Public opinion, however, was not willing to go that far.Chambers 93; Weigley Army 345
Both the regular army and the Preparedness leaders had a low opinion of the National Guard, which they saw as politicized, provincial, poorly armed, ill trained, too inclined to idealistic crusading (as against Spain in 1898), and too lacking in understanding of world affairs. The National Guard on the other hand was securely rooted in state and local politics, with representation from a very broad cross section of the U.S. political economy. The Guard was one of the nation's few institutions that (in some northern states) accepted black men on an equal footing with white men.
Democrats respond