Final answer:
The end of World War I was marked by the signing of the Treaty of Versailles, not by a single battle. The involvement of American troops provided a decisive advantage to the Allies in the final stages of the war. The Treaty of Versailles imposed harsh terms on Germany, shaping the postwar world and creating conditions that led to future conflicts.
Step-by-step explanation:
The Treaty of Versailles is often regarded as the formal conclusion to World War I. Although it is not a traditional battle, the treaty embodied the end of hostilities and the peace terms imposed primarily on Germany. It wasn't a single battle that ended WWI, but a series of events leading up to an armistice and eventual peace.
The American involvement in WWI was brief but significant. The U.S. troops' arrival in Europe in 1917 provided much-needed reinforcements to the Allied Powers at a critical time. President Woodrow Wilson's vision for the postwar world was outlined in his Fourteen Points, though much of this was not reflected as he had hoped in the Treaty of Versailles.