The United States officially entered World War I in 1917. Although the conflict began in 1914, the U.S. initially maintained a stance of neutrality. However, several factors, including unrestricted submarine warfare by Germany and the interception of the Zimmermann Telegram, shifted public opinion and policy toward intervention. In April 1917, President Woodrow Wilson asked Congress to declare war on Germany, which was granted. U.S. involvement provided a significant boost to the Allied Powers, contributing to eventual victory in the war. The entry into the war also marked a significant shift in U.S. foreign policy and its emergence as a global power.