How did the United States joining the war affect world war 1?

The United States' entry into World War I in April 1917 provided a significant boost to the Allied powers, both in terms of manpower and resources. American troops and supplies helped to bolster the exhausted Allied forces, tipping the balance against the Central Powers. Additionally, U.S. involvement brought fresh enthusiasm and a sense of urgency to the Allied efforts, contributing to the eventual defeat of Germany and its allies in November 1918. The U.S. participation also set the stage for its increased role in global affairs in the years to follow.