US Enters WWI

On April 6, 1917, the United States formally declared war on Germany, entering World War I. President Woodrow Wilson cited Germany's unrestricted submarine warfare and the Zimmermann Telegram as reasons. The arrival of over 2 million U.S. troops on the Western Front tipped the balance in favor of the Allies, leading to Germany's surrender in November 1918 and marking the U.S.'s emergence as a global superpower.