The Battle of Belleau Wood in 1918 saw U.S. Marines engage in fierce fighting against German forces in France's Belleau Wood, which was a pivotal battle that helped turn the tide of World War I in favor of the Allies. The Marines launched a counteroffensive that halted the German advance and marked the first major American combat operation of World War I, demonstrating their combat skills and earning a reputation for their bravery and tenacity in battle. Though the Marines suffered heavy casualties, their victory at Belleau Wood boosted American morale and established the Marines as a force to be reckoned with by the Germans.