CC0 Usage Conditions ApplyClick for more information. Online primary source: the coded message that proposed a German-Mexican alliance in World War I (and that helped to bring the U.S. into the war).

Key point: In the end, the Zimmermann Telegram hastened Germany’s downfall. It was one hundred years ago when Mexico almost invaded the United States. In January 1917, German foreign secretary Arthur ...

Here’s What You Need To Remember: What helped revive the exhausted British and French armies were the divisions of fresh Yank troops streaming off the transport ships and into the trenches.... Here’s ...