- The US provided much-needed military and economic support to the Allied Powers. The US sent over 2 million troops to Europe, and its factories produced vast quantities of munitions, food, and other supplies for the war effort. This helped to turn the tide of the war in favor of the Allies, who had been struggling against the German Empire and its allies.
- The US helped to demoralize the German military and civilian population. The arrival of fresh American troops on the battlefield boosted the morale of the Allied troops and made it clear to the Germans that the war was not going to end in their favor. The German people were also starting to suffer from the effects of the war, such as food shortages and inflation, and the US entry into the war only made things worse.
- The US played a key role in the peace negotiations that ended the war. President Woodrow Wilson was a leading advocate for a peace settlement based on the principles of self-determination and collective security. These principles were enshrined in the Treaty of Versailles, which was signed in 1919 and ended World War I.
Overall, the United States' entry into World War I was a major turning point in the war, and it had a significant impact on the war's outcome. The US provided vital military and economic support to the Allied Powers, helped to demoralize the German military and civilian population, and played a key role in the peace negotiations that ended the war.