On this day in 1917, some 32 months into the conflict, the United States declared war on Germany; the following December, war was also declared on Austria-Hungary, and US troops finally began arriving in numbers shortly thereafter.
Notwithstanding President Woodrow Wilson’s re-election slogan, “He Kept Us Out of War,” even before August of 1914, American opinion had been more negative toward Germany than towards most other nations in Europe. Over time, especially after reports of atrocities in Belgium in 1914 and following the sinking of the passenger liner RMS Lusitania in 1915, wherein 120 Americans perished, the US increasingly came to see Germany as the aggressor in Europe.
In 1917, with Russia experiencing Bolshevist upheaval following widespread disillusionment over the war, and with Britain and France low on monster credit extended by American banks, Germany appeared to have the upper hand in Europe; the Ottoman Empire clung to its possessions in the Middle East. Also that year, Germany made a calculated risk in resuming unrestricted submarine warfare against any vessel approaching British waters in an attempt to starve Britain into submission.
Germany broke the final straw with a secret offer to help Mexico regain territories lost through the Mexican–American War in an encoded missive known as the Zimmermann Telegram, intercepted by British Intelligence. Publication of that communique outraged Americans just as German U-boats recommenced 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 agreed.
Within a few months, thousands of American men were being drafted into the military and sent to hurried training. Women, many who had never worked outside the home before, took jobs in factories producing supplies needed for the war effort, as well as serving in ambulance corps and the American Red Cross at home and abroad. Children were enlisted to sell war bonds and plant victory gardens in support of the war effort.
The US ultimately deployed more than five-million personnel to Europe, where they encountered a war unlike any other–one waged largely in festering trenches. They saw what their Allies had already endured for years; introduction of the machine-gun, long-range artillery, aircraft, poison gas, armored tank, and other grisly tools to the business of killing. Like their European comrades, they were also subject to frequently incompetent generalship, adding to their miseries and casualties.
The First World War left a legacy of over 40 million total military and civilian casualties; 20 million deaths and 21 million wounded. This total number of deaths includes 9.7 million military personnel not less than 10 million civilians, with Germany, Russia, Austria-Hungary, France, and Great Britain each losing nearly a million lives or more.
In contrast, American losses in World War I were modest compared to those of other belligerents, with 116,516 deaths and approximately 320,000 sick and wounded of the 4.7 million men who served. Having helped win the war, the US would then lead the charge to lose the peace, dooming both Europe and Asia to a deadly repeat performance 21 years later.