More than three million American men, many of them volunteers, joined the AEF in the first twenty months of US involvement in the First World War. Of these, over 50,000 were killed on European soil. These were the Doughboys, the young men recruited from the cities and farms of the United States, who travelled across the Atlantic to aid the allies in the trenches and on the battlefields. Without their courage and determination, the outcome of the war would have been very different. Why did America become involved in the First World War? What was the fighting experience of the AEF in France and Russia? Most importantly, why has the vital contribution made by the Americans been largely neglected by historians of the Great War? In this fascinating study, based on original research, Gary Mead adjusts the balance of history in favor of these unsung heroes. Drawing on a rich selection of engaging personal accounts, he brings us the stories of the young men whose courage and tenacity changed the course of the war.