Final answer:
The U.S. troops significantly aided the Allied victories at Cantigny, Château-Thierry, and Belleau Wood in 1918, which were pivotal in repelling the German advance in France during World War I.
Step-by-step explanation:
The United States reinforcements contributed greatly to three allied victories in France at the following locations: Cantigny, Château-Thierry, and Belleau Wood.
These battles occurred during the Spring and Summer of 1918, which saw American forces, fighting side-by-side with British and French troops, effectively repel the German offensive and set the stage for subsequent victories.
The first significant American-led offensive was at the Battle of Cantigny on May 28, where American troops overran the German headquarters.
Then, the battles of Château-Thierry and Belleau Wood followed, witnessing some of the most brutal fighting for American forces, including numerous casualties.
Nevertheless, these conflicts were crucial in turning the tide of the war against Germany and demonstrating the American troops' fortitude and bravery.