On June 28, 1914, a Serbian terrorist assassinated Archduke Franz Ferdinand, the heir to the Austro-Hungarian throne. Austria-Hungary avenged their leader by declaring war on Serbia. What on other continents may have remained a localized conflict instead ignited a series of complicated alliances in imperialistic Europe. Serbia allied with Russia; Russia allied with France. In turn, Austria-Hungary joined forces with Germany. Soon, Great Britain joined Russia and France while Turkey joined Germany and Austria-Hungary. By early August of 1914, these nations were embroiled in a war of international proportions and control of Europe was on the line.
American involvement in the war was by no means a given. Because it provided a haven to immigrants from all of the European countries already involved in the conflict, choosing allegiances was a complicated matter. In 1916, US President Woodrow Wilson won re-election campaigning on a isolationist platform that explicitly opposed the country's involvement in the European war. Wilson’s government managed to keep this promise for three years. But events leading up to the entry of the United States in 1917—namely German torpedoes striking American ships—rendered it impossible to avoid the conflict.