The Great War caught a generation of American soldiers at a turning point in the nation's history. At the moment of the Republic's emergence as a key player on the world stage, these were the first Americans to endure mass machine warfare, and the first to come into close contact with foreign peoples and cultures in large numbers. What was it like, Richard S. Faulkner asks, to be one of these foot soldiers at the dawn of the American century? How did the doughboy experience the rigors of training and military life, interact with different cultures, and endure the shock and chaos of combat?...