Zimmerman Telegram (telegram)

The Zimmerman Telegram was a secret message sent in 1917 by Germany's foreign minister to Mexico, proposing an alliance against the United States. Germany promised Mexico the return of territories like Texas and Arizona if they joined the war. British intelligence intercepted and decoded the telegram, then shared it with the U.S. This revelation angered Americans and helped sway public opinion in favor of joining World War I. The telegram was a turning point that contributed to the U.S. decision to enter the conflict on the side of the Allies.