This Day in History: February 26
British authorities handed Walter Hines Page, the U.S. ambassador to Britain, a copy of the Zimmermann Telegram, a coded message from Zimmermann to Count Johann von Bernstorff, the German ambassador to Mexico. In the telegram, intercepted and deciphered by British intelligence in late January, Zimmermann instructed his ambassador, in the event of a German war with the United States, to offer significant financial aid to Mexico if it agreed to enter the conflict on the Germans' side. Germany also pledged to restore to Mexico the lost territories of Arizona, Texas, and New Mexico.
The State Department quickly sent a copy of the Zimmermann Telegram to President Woodrow Wilson, who was shocked by the note’s content and the very next day proposed to Congress that the U.S. should start arming its ships against potential German attacks. Wilson also authorized the State Department to publish the telegram; it appeared on the front pages of American newspapers on March 1. Many Americans were mortified and presumed the note was a forgery; two days later, however, Zimmermann himself declared that it was genuine.
The Zimmermann Telegram helped turn the U.S. public, already angered by repeated German attacks on U.S. ships, firmly against Germany. On April 2, President Wilson, who had at first sought a peaceful resolution to World War I, urged immediate U.S. entrance into the war. Four days later, Congress formally declared war against Germany.