Many of the most vivid American accounts of the First World War were written not by front-line troops, but by non-combatant volunteers who witnessed the conflict as nurses, aid-workers or ambulance drivers. Drawn to the war-zone by a humanitarian desire to serve, or simply by the lure of adventure, these volunteers often came to feel a sense of unease at their own complicity in the machinery of war, and developed a powerful sense of detachment from the military systems within which they worked. This chapter explores a range of such writers, noting how early war memoirs established repeating tropes that would be adapted and subverted by later more nuanced responses to the war. For some, the insight generated by these wartime experiences, and the verbal skills required to articulate them, would inform a lifetime of literary production.