The first of five annual races began on May 5, 1950 and was entered by racers from all over the world representing virtually every motor sport: Formula One, sports cars, rallying, stock cars, endurance racing, hill climbing, and drag racing. Because it started at the border with Texas, it was especially attractive to all types of American race drivers from Indy cars to NASCAR. Bill France, the founder of NASCAR, was there for the first race as well as later races. The Mexican government's representatives worked closely with the American Automobile Association and other motor sports groups in the United States to organize and promote the event which was limited to stock sedans with five seats. Piero Taruffi and Felice Bonetto, both Italian F1 drivers, entered a pair of Alfa Romeo coupes specially constructed for the event. However, many of the 132 competitors were ordinary unsponsored citizens from the United States, Mexico, and elsewhere. The entrants included nine women drivers.