World War 1 By jmosely Jun 28, 1914 Assassination of Archduke Ferdinand Archduke Ferdinand Jul 28, 1914 Austria-Hungary Declares War on Serbia Austria-Hungary declares war in serbia May 23, 1915 Italy declares war on Austria-Hungary Italy declares war on Austria-Hungary Oct 14, 1915 Bulgaria declares war on Serbia Bulgaria declares war on Serbia Period: Feb 21, 1916 to Dec 18, 1916 Battle Of Verdun battle of verdun Feb 25, 1917 Zimmerman telegram Zimmerman Telegram Apr 6, 1917 U.S. enters the war u.s. enters the war Period: Apr 9, 1917 to Apr 12, 1917 Battle of Vimy Ridge Battle of vimy ridge Jun 7, 1917 Battle of Messines Ridge Battle of Messines Ridge Period: Jul 31, 1917 to Nov 6, 1917 Battle of Passchendaele Battle of Passchendaele Mar 3, 1918 Treaty of Brest-Litovsk germany and russia peace Period: Jun 1, 1918 to Jun 26, 1918 Battle of Belleau Wood Battle of Belleau Wood Nov 11, 1918 Armistice Day [Armistice Day](www.eyewitnesstohistory.com/armistice.htm) Period: Jun 28, 1919 to Jan 21, 1920 treaty of versailles treaty of versailles
