What was the Zimmermann telegram?
It was a message sent from Arthur Zimmermann to the Mexican government. In it, Zimmerman explained that the United States was waiting too long to enter the war and it was German's goal to get them involved. Zimmermann wanted Mexico to lead an invasion against the U.S. with Germany's support. In exchange for siding with the Germans, Mexico would receive New Mexico, Texas, and Arizona (all of these states were taken from Mexico by the U.S. in a previous war). Although Mexico never followed through with this plan, many Americans found out about it and saw this as a reason to enter the war against Germany.