The Zimmermann Telegram (also called the Zimmermann Note) was a telegram sent to Mexico from Germany on January 16, 1917. It was what made America enter World War I. It is named for the German man who sent it, Arthur Zimmermann. Zimmermann was the German Foreign Secretary (took care of things with other countries). Zimmermann sent it to the German ambassador in the United States, Johann von Bernstorff. Bernstorff then sent it to the German ambassador in Mexico, Heinrich von Eckardt.