"Those who are not for us are against us." 
            SC Handbook on the War, September 1917

While the continent of Europe had been embroiled in death and destruction since 1914, the United States had remained neutral. In spite of efforts by President Wilson to remain out of the war a growing dispute with Imperial Germany over the status of neutral shipping on the high seas led to a growing rift. During the first two years of war U-boats sank American vessels in spite of their status. When the Zimmerman telegram became public in February 1917 most Americans believed war was inevitable. Sent by the German foreign ministry, the infamous document offered Mexico the return the Southwestern states of the United States if they agreed to join the Central Powers.

After President Wilson asked Congress to declare war on Germany, they did so on April 6, 1917 with only a few legislators dissenting.