World War 1 By maddywester Jun 28, 1914 WWI Begins Franz Ferdinand assassinated Sep 6, 1914 First Battle of Marne starts Apr 22, 1915 Poison Gas first used by Germany May 7, 1915 Sinking of the Lusitania Period: Feb 22, 1916 to Dec 18, 1916 Battle of Verdun May 31, 1916 Battle of Jutland Period: Mar 8, 1917 to Jun 16, 1923 Russian Revolution Apr 6, 1917 United States Declares War Period: Jul 15, 1918 to Aug 6, 1918 Second Battle of Marne Aug 8, 1918 One Hundred Days Offensive Begins Nov 11, 1918 Armistice with Germany signed Jun 18, 1919 Treaty of Versailles