Apr. 6—United States declares war on Germany.
Apr. 8—Austria-Hungary severs diplomatic relations with the United States.
Apr. 9-May 14—British successes in Battle of Arras; (Vimy Ridge taken Apr. 9).
Apr. 16-May 6—French successes in Battle of the Aisne between Soissons and Rheims.
Apr. 20—Turkey severs relations with United States.
May 4—American destroyers begin co-operation with British navy in war zone.
May 15-Sept. 15—Great Italian offensive on Isonzo front (Carso Plateau). Capture of Gorizia, Aug. 9. Monte Santo taken Aug. 24. Monte San Gabrielle, Sept. 14.
May 15—Gen. Petain succeeds Gen. Nivelle as commander in chief of the French armies.
May 17—Russian Provisional Government reconstructed. Kerensky (formerly minister of justice) becomes minister of war.
May 18—President Wilson signs selective service act.