The president of the United States during World War I was Woodrow Wilson. He served as the 28th president from 1913 to 1921. Initially, Wilson maintained a policy of neutrality when the war broke out in 1914, but after a series of provocations including unrestricted German submarine warfare and the Zimmermann Telegram, he led the U.S. into the war in 1917 to "make the world safe for democracy." Wilson then guided the country through the conflict and was a key architect of the League of Nations after the war