The American Field Service (AFS) was founded shortly after the outbreak of World War I, when Americans living in Paris volunteered as ambulance drivers at the American Hospital of Paris. Under the leadership of Inspector General A. Piatt Andrew, AFS participated in every major French battle and carried more than 500,000 wounded. By the end of World War I, 2,500 men had served as ambulance or camion drivers in the American Field Service with the French Armies.
Stephen Galatti, who had been Assistant General Inspector during part of World War I, became Director General of the organization in 1936 after Andrew’s death. Under his leadership, the AFS ambulance service was reactivated in 1939 at the start of the Second World War. Stephen Galatti, his staff at New York Headquarters, local committees, and regional representatives around the country (including William DeFord Bigelow in Boston) actively raised funds and recruited ambulance drivers to assist foreign forces overseas. By mid-1944 AFS became a participating member of the National War Fund, an organization sponsored by the Federal Government to be a central collecting bureau for relief organizations, and AFS ceased raising money on its own.
American volunteers first drove ambulances with the 19th Train of the Tenth French Army in 1940. The first unit of seventeen men (FR 1) sailed from New York on March 23, 1940, and joined eighteen men who had already volunteered in Europe. After the German invasion and the establishment of Vichy France in June 1940, AFS halted service in France and began a series of interim activities. The remaining ambulances in France were loaned to the American Red Cross for use in carrying supplies to the prison camps, and were subsequently given to the Secours Nationale, a relief organization. AFS also solicited funds for ambulances for the American Ambulance, Great Britain, and sent ambulance drivers to assist the British forces in Kenya and the Hadfield-Spears Hospital Unit operating with the Free French Forces in Syria from 1940 to 1941.
AFS officially aligned with the British forces in 1941. The AFS overseas headquarters was set up within the perimeter of the General Headquarters, Middle East Forces (GHQ MEF) in Cairo in December 1941, and the first unit of ambulance drivers embarked for the Middle East that same month (though they were rerouted to Bombay due to the outbreak of war with Japan.) As the war progressed AFS ambulance drivers served in the Middle East, North Africa, Italy, Germany, India, and Burma with the British military, the Free French forces (Forces Françaises Libres, later called the Forces Françaises Combattantes), and again in France with the First French Army. AFS also intended to send a unit to China to assist on the eastern front of the war, and had plans to formulate an Air Ambulance Squadron (AAS), but the war ended before either could fully materialize. The 2,196 American Field Service ambulance drivers served alongside French, British, Polish, Australian, New Zealand, Indian, and South African troops, and carried over 700,000 Allied and Axis casualties by the end of the war.