The roadster, a popular vehicle style in early twentieth-century America is characterized by its lack of windows and the ability to add a canopy to the chassis' top. Generally, roadsters were affordable, everyday cars designed for the middle class and the least expensive models sold by manufacturers. The 1909 Keystone Six-Sixty Roadster was not designed for everyday use, however. It is an early racing vehicle.
The minimal bodywork and lack of fenders emphasizes it is designed for speed. With the production of racing cars, motor sports quickly gained popularity in the Únited States.
C.P. Munch and R.M. Allen manufactured this particular roadster from 1909 until 1910 when the plant north of Pittsburgh in DuBois, Pennsylvania closed. The high-powered Keystone Six-Sixty was priced at $2,250, which was very expensive for its time.Source - Frick Car Museum