NASCAR races run counter-clockwise because left turns are safer on oval tracks since the drivers sit on the left side of the vehicle, and the right-hand side would hit the wall in an accident. Left-hand turns are also easier for the driver to make while sitting on the left side.
NASCAR races held on road courses, Sonoma and Watkins-Glen, have both right and left turns. AUSCAR, the Australian version of NASCAR, runs clockwise races on oval tracks, requiring right turns, because their drivers are on the right side of the car. NASCAR's first race was held on the dirt track at Charlotte Speedway in 1949.