Who served as President during World War I?

Woodrow Wilson served as President during World War I, which lasted from 1914 to 1918. He held office from 1913 until 1921 and was a pivotal figure during the war, leading the United States into the conflict in 1917 after initially promoting a policy of neutrality. Wilson's administration worked on various domestic and foreign issues, but his notable contributions during the war included advocating for the League of Nations, which aimed to ensure lasting peace following the war's end. His Fourteen Points speech outlined his vision for a just and lasting peace, emphasizing self-determination and collective security, concepts that would influence the post-war world.

In contrast, other presidents mentioned did not serve during World War I. Theodore Roosevelt was in office from 1901 to 1909, Franklin Roosevelt served during World War II, and Harry Truman took office after the death of Franklin Roosevelt, during World War II and the early Cold War period. Therefore, Wilson's role in World War I is historically significant, making him the correct answer to this question.