The words "Retreat? Hell, we just got here," has become a central part of the Marine Corps legend, indicative of their reputation for dogged determination and bravery. The iconic words were uttered at the height of the fierce battle for Belleau Wood and became a defining moment for the Corps, establishing their "first to fight" ethos in the public eye. This history follows the experiences of the Marines during the Great War, from their training in the United States and France through the battles in the trenches and battlefields of the Western Front and right up to their occupation duties in the Rhineland. Packed with firsthand accounts and detailed information from the USMC History Division at Quantico and published to coincide with the one hundredth anniversary of America's involvement in World War I, this is a timely analysis of one of the Marines defining moments.