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The U.S. Enters World War I

The United States maintained a policy of neutrality following the outbreak of European war in August 1914.  Germany’s sinking of neutral ships carrying cargo to Great Britain led to diplomatic tension with the United States throughout 1915 and 1916.

In January 1917 a telegram from German foreign minister Alfred Zimmermann to the Mexican government proposing a military alliance between Germany and Mexico was intercepted by the British and turned over to the U.S. government.  The “Zimmermann Telegram” was published in U.S. newspapers on March 1, 1917.  In addition, Germany’s resumption of unrestricted submarine warfare on February 1 had increased the losses of American ships and lives.  On April 2, President Woodrow Wilson addressed a joint session of Congress requesting a declaration of war against Germany stating in part:

 The present German submarine warfare against commerce is a warfare against mankind. It is a war against all nations. American ships have been sunk, American lives taken…

 I advise that the Congress declare the recent course of the Imperial German government to be in fact nothing less than war against the government and people of the United States; that it formally accept the status of belligerent which has thus been thrust upon it; and that it take immediate steps… to bring the government of the German Empire to terms and end the war.

 The world must be made safe for democracy. Its peace must be planted upon the tested foundations of political liberty.

 A resolution declaring war on the German government passed the Senate on April 4 and the House on April 6.  President Wilson’s signature on April 6, 1917, took the nation to war.

Following our entry into World War I the United States experienced its largest military mobilization up to that time.  The United States Army grew from a total force of 218,324 Regular Army, National Guard, and Army Reserve soldiers at the beginning of the war to an army of over 3.6 million men.  Navy and Marine inductees brought the total number of U.S. military personnel to just over 4 million when the war ended on Armistice Day, November 11, 1918.