World War I By ceciliaa4 Jun 28, 1914 Franz Ferdinand Assassination The assassination sparked 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 Lusitania 1916 Wilson is reelected as President; Pledged American neutrality 1917 Zimmermann Note 1917 US declares war 1917 Bolsheviks, led by Vladimir Lenin, overthrow the Russian government Nov 11, 1918 War ends Jun 28, 1919 Treaty of Versaillies
