War broke out in Europe in August 1914, with Germany and Austria-Hungary the main combatants on one side (Central Powers) and Britain, France, and Russia the primary countries opposing them (Allies). U.S. President Woodrow Wilson declared the nation's neutrality but, in several ways, seemed to favor the Allies. U.S. banks loaned nearly ten times more money to the Allies as to the Central Powers, giving businesses a stake in Allied success. When the British violated the rights of neutrality by detaining neutral ships, Wilson protested mildly. Yet when the Germans sank the British passenger liner the Lusitania, killing 128 Americans, Wilson's response was harsh.
By 1917, the Germans needed to take desperate action to stave off defeat. By renewing U-boat warfare in an attempt to cut off trade to Britain and by trying to get Mexico to declare war on the United States, Germany drew the United States into the war on the side of the Allies. War was declared on April 2.
Within a few months, Americans were being drafted into the military. Others, including women who had never worked outside the home before, took jobs in factories producing supplies needed for the war effort. As you read the sources in this set, look for evidence of the different roles Americans played in the war effort, as well as the effects of the war on Americans' lives.
To find additional sources on this topic in American Memory, you might use the phrases World War One or The Great War, or look for specific subjects, such as munitions plants or defense industries.