The history of The American Legion, a U.S. war veterans' organization headquartered in Indianapolis, Indiana, began in Paris, France, March 15 to 17, 1919, by a thousand commissioned officers and enlisted men, delegates from all the units of the American Expeditionary Forces to an organization caucus meeting, which adopted a tentative constitution and selected the name "American Legion." It was subsequently chartered by the 66th U.S. Congress on September 16, 1919.