World War I started in 1914 with assassination of Archduke Francis Ferdinand of Austria-Hungary in Sarajevo.   At the start of World War I, President Wilson had declared the neutrality of the United States.  Most American opposed U.S. involvement in a European war.  But the sinking of the the liner Lusitania and other German actions against civilians drew American sympathies to the Allies. On April 6, 1917 the United States joined the Allies by declaring war on Germany.
   WWI caused immeasurable destruction.  Nearly 10 million soldiers died as a result of the war.  American deaths numbered 116516. 
  World War I ended on November 11, 1918 with Germany signing an armistice