Lesson 3: U.S. Involvement in WWI

The United States entered World War I in April 1917, more than two and a half years after the war had begun.

What were the reasons for U.S. entry into WWI?

Homefront

During World War I, the United States homefront experienced significant changes and challenges as the country shifted from a peacetime to a wartime economy. 

• Mobilization of the economy

• Propaganda and censorship

• Women's role

• Civil liberties

• Immigration and racism

• Food and fuel shortages

Treaty of Versailles

Wilson faced a tough political battle when he returned from Paris. Some senators were very opposed to the treaty. A group of 12-18 senators, who became known as “irreconcilables,” completely opposed all parts of the treaty. Other senators, led by Henry Cabot Lodge from Massachusetts, were concerned about the terms for the League of Nations but were willing to negotiate those terms and then sign the treaty. These Senators became known as “reservationists” because they would only agree to the treaty if it included certain reservations (terms) that addressed aspects of the treaty that they didn’t like.