Mar. 24—French steamer "Sussex" is torpedoed without warning; about 80 passengers, including American citizens, are killed or wounded.
Mar. 25—Department of State issues memorandum in regard to armed merchant vessels in neutral ports and on the high seas.
Mar. 27-29—United States Government instructs American ambassador in Berlin to inquire into sinking of "Sussex" and other vessels.
Apr. 10—German Government replies to United States notes of March 27, 28, 29, on the sinking of "Sussex" and other vessels.
Apr. 17—Russians capture Trebizond.
Apr. 18—United States delivers what is considered an ultimatum that unless Germany abandons present methods of submarine warfare United States will sever diplomatic relations.
Apr. 19—President addressed Congress on relations with Germany.
Apr. 24-May 1—Insurrection in Ireland.
Apr. 29—Gen. Townshend surrendered to the Turks before Kut-el-Amara.
May 4—Reply of Germany acknowledges sinking of the "Sussex" and in the main meets demands of the United States.