World War I By HudsonA Jun 28, 1914 Franz Ferdinand Assassination The assassination of the Archduke of Austria caused the beginning of World War I Jul 28, 1914 Austria-Hungary declares war on Serbia 1915 First use of gas as a weapon by the Germans May 7, 1915 Sinking of the Lusitansia 1917 Wilson reelected; pledged american neutrality 1917 Zimmermann Note 1917 U.S Declares war 1917 Bolshevicks led by Lenin overthrown russian goverment Nov 11, 1918 War Ends May 28, 1919 Treaty of Versailles
