On Fourth of July weekend in 1924, Marion Martins flies past some of the best race car drivers of her time and takes home two trophies from the famous North Shore racetrack in Chicago. In 1926, on the beaches of Daytona, Florida, Joan LaCosta breaks a world speed record at 145 miles per hour. But Martins and LaCosta never face one another on the close-knit circuit of early American auto racing.