This descriptive inventory of the American Field Service in World War I begins with documents prior to the actual date of operation of the American Field Service in France--April 1915--and ends in September 1917 when the AFS was militarized by the U.S. Army and ceased to exist as an independent body for the duration of the war. The AFS ambulance service was the model for the foundation of the American Army Ambulance Service of 1917, and the AFS Transport Corps served as the prototype of the U.S. Army Motor Transport Corps. Included here are over fifty unique, previously unpublished photos from the AFS photographic archives. Many of these rare historical photographs were donated by World War I ambulance and motor transport drivers. These archives enhance the reader's understanding of the activity of the AFS during that period and document the role of volunteer American ambulance drivers serving with the French armies in World War I prior to U.S. entry in 1917. This book is made possible by a grant from the National Historical Publications and Records Commission and is intended both as a guide to the AFS archives and as an invitation to use the papers for a closer understanding of American and French-American relations during World War I. Series descriptions, a concise historical rendering of the AFS from 1914-1917, an essay on sources, and box and folder lists are included. An index and information on the photographic archives complete what will prove an invaluable resource for students and scholars of medical services and of military history, particularly World War I.