February 1917

Saturday 03:

World War I: The United States breaks off diplomatic relations with Germany a day after Germany announces a new policy of unrestricted submarine warfare.

Monday 05:

The Congress of the United States passes a law banning most Asian immigration.

Saturday 24:

World War I: The U.S. ambassador to the United Kingdom is given the Zimmermann Telegram, in which Germany pledges to ensure the return of New Mexico, Texas, and Arizona to Mexico if that country declares war on the United States.