AFS Intercultural Programs (or AFS, originally the American Field Service) is an international youth exchange organization. It consists of over 50 independent, not-for-profit organizations, each with its network of volunteers, professionally staffed offices, volunteer board of directors and website. In 2015^[update], 12,578 students traveled abroad on an AFS cultural exchange program, between 99 countries. The US-based partner, AFS-USA, sends more than 1,000 US students abroad and places foreign students with more than 2,000 US families each year. As of 2022, more than 500,000 people have gone abroad with AFS and over 100,000 former AFS students live in the US.

When war broke out in 1914, the American Colony of Paris organized an "ambulance"—the French term for a temporary military hospital—just as it had done in the Franco-Prussian War of 1870 when the "American Ambulance" had been under tents set up near the Paris home of its founder, the celebrated Paris-American dentist, Thomas W. Evans. The "American Ambulance" of 1914 took over the premises of the unfinished Lycée Pasteur in the suburb of Neuilly-sur-Seine—and was run by the nearby American Hospital of Paris.

The volunteer drivers of 1914 found themselves behind the wheels of motorized, not horse-driven, vehicles: Model-Ts, purchased from the nearby Ford plant in Levallois-Perret.

In the fall of 1914, when the war front moved away from Paris, the American Ambulance set up an outpost in Juilly and sent out detached units of volunteer drivers to serve informally with the British and Belgian armies in the north. In early 1915, one of those drivers, A. Piatt Andrew, was appointed "Inspector of Ambulances" by Robert Bacon, head of the American Ambulance and one of Andrew's colleagues from the Taft Administration.

The newly appointed inspector toured the ambulance sections of Northern France and learned that the American volunteers were bored with so-called "jitney work," transporting wounded soldiers from railheads to hospitals far back from the front lines. French army policy prohibited foreign nationals from traveling into battle zones.

In March 1915, Andrew met with Captain Aimé Doumenc, head of the French Army Automobile Service and pleaded his case for the American volunteers. They desired above all, he said, "to pick up the wounded from the front lines..., to look danger squarely in the face; in a word, to mingle with the soldiers of France and to share their fate!" Doumenc agreed to give Andrew a trial. The success of Section Z was immediate and overwhelming, and by April 15, 1915, the French created American Ambulance Field Service operating under French Army command. Sections of about 30 drivers each were assigned to individual French Army divisions. The volunteer drivers at first joined for six months at a time; some received acting officer uniforms and ranks to work with the French officers that commanded the units.

This marked the formal beginning of American Ambulance Field Service, three units of which made their mark during battles in northern France, the Champagne, Verdun and the Vosges.

By the summer of 1916, the Field Service severed its ties with the American Ambulance and moved its operations from cramped quarters in Neuilly to Paris, onto the spacious grounds of the Delessert château at 21 rue Raynouard in the Passy area of Paris. There, it grew rapidly over the next year, continuing to provide "sanitary sections" to the French Army, while also serving as a recruitment source of combat pilots for the newly formed Escadrille Lafayette, one of whose prime movers, Edmund L. Gros, was the Field Service's in-house physician.