What significant action did Germany take in 1917 that contributed to the U.S. entering World War I?

• A. They declared war on the United States
• B. They sent the Zimmerman Note to Mexico
• C. They attacked American shipping vessels
• D. They formed an alliance with Japan

Answer: (B)

The decision by Germany to send the Zimmerman Note to Mexico in 1917 was a pivotal factor in the United States' eventual entry into World War I. The Zimmerman Note was a secret diplomatic communication sent by German Foreign Minister Arthur Zimmermann to the Mexican government, proposing a military alliance between Germany and Mexico should the United States enter the war. In the note, Germany promised to support Mexico in reclaiming territories lost to the U.S., namely Texas, New Mexico, and Arizona.

This communication was intercepted and decoded by British intelligence and then passed on to the U.S. government. The revelation of Germany's intentions to entice Mexico into war against the United States outraged the American public and further inflamed anti-German sentiment. Coupled with other factors, such as unrestricted submarine warfare and economic ties to the Allies, the Zimmerman Note galvanized public opinion and led to a shift in U.S. foreign policy, ultimately culminating in the declaration of war against Germany in April 1917. This event marked a significant turning point in the war, as the United States played a crucial role in the eventual victory of the Allies.