The Vanderbilt cup under the control of the American Automobile Association (AAA) turned their backs on the Grand Prix cars of Europe in a quest to have an American car take the Cup. The Europeans seeing their advantage disappear by the rule changes stayed away from the Vanderbilt Cup and chose to enter the new American Grand Prize instead. Organized by the Automobile Club of America (ACA) rivals of the AAA this group followed the rules stipulated by the Automobile Club of France (ACF).
