In January 1917, Germany resumed unrestricted submarine warfare, realizing it would mean American entry. The German Foreign Minister, in the Zimmermann Telegram, invited Mexico to join the war as Germany 's ally against the United States. In return, the Germans would finance Mexico 's war and help it recover the territories of Texas, New Mexico, and Arizona. The United Kingdom intercepted the message and presented it to the U.S. embassy in the U.K. From there it made its way to President Wilson who released the Zimmermann note to the public, and Americans saw it as casus belli. Wilson called on antiwar elements to end all wars, by winning this one and eliminating militarism from the globe. He argued that the war was so important that the U.S. had to have a voice in the peace conference. After the sinking of seven U.S. merchant ships by submarines and the publication of the Zimmermann telegram, Wilson called for war on Germany, which the U.S. Congress declared on 6 April 1917.
what was the major reason for united states entry into world war 1
the sinking of seven U.S. merchant ships by submarines and the publication of the Zimmermann telegram