Feb. 28—"Zimmerman note" revealed.
Mar. 4—Announced that the British had taken over from the French the entire Somme front; British held on west front 100 miles, French 175 miles, Belgians 25 miles.
Mar. 11—Bagdad captured by British under Gen. Maude.
Mar. 11-15—Revolution in Russia, leading to abdication of Czar Nicholas II (Mar. 15). Provisional Government formed by Constitutional Democrats under Prince Lvov and M. Milyukov.
Mar. 12—United States announced that an armed guard would be placed on all American merchant vessels sailing through the war zone.
Mar. 17-19—Retirement of Germans to "Hindenburg line." Evacuation of 1,300 square miles of French territory, on front of 100 miles, from Arras to Soissons.
Mar. 22—United States formally recognized the new government of Russia set up as a result of the revolution.
Mar. 26—The United States refused the proposal of Germany to interpret and supplement the Prussian Treaty of 1799.
Mar. 27—Minister Brand Whitlock and American Relief Commission withdrawn from Belgium.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.