World War I By Chi_01 Jun 28, 1914 Archduke Ferdinand Archduke Ferdinand Jul 28, 1914 Austria-Hungary declares war on Serbia Austria-Hungary declares war on Serbia Oct 11, 1916 Greece declares war on Austria-Hungary, Bulgaria, Germany and the Ottoman Empire Greece declares war on Austria-Hungary, Bulgaria, Germany and the Ottoman Empire Apr 6, 1917 United States declares war on Germany United States declares war on Germany Nov 11, 1918 Armistice Day Armistice Day Jun 28, 1919 Treaty of Versailles Treaty of Versailles
