Mar. 12 United States announces that an armed guard will be placed
             on all American merchant vessels sailing through the war
             zone.

Mar. 17-19 Retirement of Germans to the “Hindenburg line” (page 118).

Mar. 24 Minister Brand Whitlock and American Relief Commission
             withdrawn from Belgium.

Apr. 2 President Wilson asks Congress to declare the existence of
             a state of war with Germany.

Apr. 6 United States declares war on Germany.

Apr. 8 Austria-Hungary severs diplomatic relations with the United
             States.

Apr. 9- British successes in battle of Arras (Vimy Ridge taken
May 14 Apr. 9).

Apr. 16- French successes in battle of the Aisne between Soissons and
May 6 Rheims.

Apr. 21 Turkey severs relations with United States.

May 4 American destroyers begin cooeperation with British navy in
             war zone.

May 15- Great Italian offensive on Isonzo front. 
Sept. 15

May 15 Gen. Petain succeeds Gen. Nivelle as commander in chief of
             the French armies.

May 18 President Wilson signs selective service act.

June 7 British blow up Messines Ridge, south of Ypres, and capture
             7,500 German prisoners.

June 10 Italian offensive in Trentino.

June 12 King Constantine of Greece forced to abdicate.

June 26 First American troops reach France.

June 29 Greece enters war against Germany and her allies.

July 1 Russian army led in person by Kerensky, the Minister of War,
             begins an offensive in Galicia, ending in disastrous retreat
             (July 19-Aug. 3).

July 20 Kerensky succeeds Prince Lvov as premier of Russia.

July 30 Mutiny in German fleet at Wilhelmshaven and Kiel.  Second
             mutiny Sept. 2.

July 31- Battle of Flanders (Passchendaele Ridge); British successes. 
Nov.

Aug. 15 Peace proposals of Pope Benedict published (dated Aug. 1).
             United States replies Aug. 27; Germany and Austria,
             Sept. 21.

Aug. 15 Canadians capture Hill 70, dominating Lens.

Aug. 19-24 New Italian drive on the Isonzo front.

Aug. 20-24 French attacks at Verdun recapture high ground lost in 1916.

Sept. 3 Riga captured by Germans.

Sept. 8 Luxburg dispatches ("Spurlos versenkt”) published by United
             States.

Sept. 15 Russia proclaimed a republic.

Oct. 17 Russians defeated in a naval engagement in the Gulf of Riga.