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World War One: Declarations of War

According to the U.S State Department's list, the nations involved in the conflict made declarations of war as follows:

Aug. 28, 1914Austria against Belgium
Aug. 27, 1914Austria against Japan
Aug. 9, 1914Austria against Montenegro
Aug. 6, 1914Austria against Russia
July 28, 1914Austria against Serbia
Aug. 4, 1914Belgium against Germany
Oct. 26, 1917Brazil against Germany
Oct. 14, 1915Bulgaria against Serbia
Aug. 14, 1917China against Austria
Aug. 14, 1917China against Germany
May 23, 1918Costa Rica against Germany
Apr. 7, 1917Cuba against Germany
Dec. 16, 1917Cuba against Austria-Hungary
Aug. 13, 1914France against Austria
Oct. 16, 1915France against Bulgaria
Aug. 3, 1914France against Germany
Nov. 5, 1914France against Turkey
Aug. 4, 1914Germany against Belgium
Aug. 3, 1914Germany against France
Mar. 9, 1916Germany against Portugal
Sept. 14, 1916Germany against Rumania
Aug. 1, 1914Germany against Russia
Aug. 13, 1914Great Britain against Austria
Oct. 15, 1915Great Britain against Bulgaria
Aug. 4, 1914Great Britain against Germany
Nov. 5, 1914Great Britain against Turkey
Nov. 28, 1916Greece (Provincial Government) against Bulgaria
July 2, 1917Greece against Bulgaria
Nov. 28, 1916Greece (Provincial Government) against Germany
July 02, 1917Greece against Germany
Apr. 22, 1918Guatemala against Austria-Hungary
Apr. 22, 1918Guatemala against Germany
July 15, 1918Haiti against Germany
July 19, 1918Honduras against Germany
May 24, 1915Italy against Austria
Oct. 19, 1915Italy against Bulgaria
Aug. 28, 1916Italy against Germany
Aug. 21, 1915Italy against Turkey
Aug. 23, 1914Japan against Germany
Aug. 4, 1917Liberia against Germany
Aug. 8, 1914Montenegro against Austria
Aug. 9, 1914Montenegro against Germany
May 24, 1918Nicaragua against Germany
Dec. 10, 1917Panama against Austria
Apr. 7, 1917Panama against Germany
Nov. 23, 1914Portugal against Germany (authorizing intervention)
May 19, 1915Portugal against Germany (granting military aid)
Aug. 27, 1916Rumania against Austria (accepted by Austria's allies)
Oct. 19, 1915Russia against Bulgaria
Aug. 7, 1914Russia against Germany
Nov. 3, 1914Russia against Turkey
May 24, 1915San Marino against Austria
Oct. 16, 1915Serbia against Bulgaria
Aug. 6, 1914Serbia against Germany
Dec. 2, 1914Serbia against Turkey
July 22, 1917Siam against Austria
July 22, 1917Siam against Germany
Nov. 23, 1914Turkey against Allies
Aug. 29, 1916Turkey against Rumania
Dec. 7, 1917United States against Austria-Hungary
Apr. 6, 1917United States against Germany