Oval track racing seems to deriving from the early use of horse racing tracks as venues for auto races. Even today, occasionally horse tracks such as the one in Del Mar, California, are diverted to auto racing activities, and many county fairground tracks started as horse tracks.
There are a number of variations on oval track racing that exist in North America. Some of the differences are based on car types; others on the type of surface used.
The best known oval track events in North America are those put on by NASCAR. At the present time, the North American Motorsports Pages do not have a section devoted to NASCAR racing, but NASCAR has their own home page at http://www.nascar.com/. The primary NASCAR series (Winston Cup, Busch Grand National, Super Trucks) run on pavement, but the secondary ones may run on either dirt or on pavement.
Other North American stock car organizations include ARCA and ASA. Finally, there are many small sanctioning bodies and independent ("Outlaw") tracks; a common bottom run on the stock car ladder is "Street Stock", which may be seen at oval tracks all over the country.
The current state of Indy Car racing is too complex to explain in a short blurb. At the present time there are two competing sanctioning bodies: ChampCar (formerly CART) which sanctions the PPG CART World Series; and the IRL ("Indy Racing League"), a recent joint venture of USAC (United States Auto Club) and the management of the Indianapolis Motor Speedway. The series sanctioned by Champcar runs on a mixture of Road Courses, Street Courses, and Ovals; the IRL series runs entirely on Ovals. The car specifications were quite similar in 1996, since the IRL was using 1995 spec cars comparable to the cars used in the CART series, but thee IRL is implemented a substantially different specification for its cars in 1997.
There had been some litigation between ChampCar and the IRL over the rights to the name "Indycar"; this has recently been resolved in an out of court settlement. ChampCar gave up the name Indycar, which it had previously used under license from IMS. IMS agreed in turn not to use Indycar as a brand name before 2002. Finally, both agreed that the term Indycar is now a generic name for the top level of open wheel racing in the US, and may be used in such manner by fans and the media to refer to either series.
Both sides have web sites where one may read about two very different viewpoints on the situation. CART's site is http://www.champcarworldseries.com/ (note recent domain name change); the IRL site is http://www.indyracingleague.com/irl/.
CART also sanctions a series called Indy Lights, a feeder series for young drivers which also runs on a mixture of Ovals and Road courses. Whether this series will have to change names as a result of the court settlement is unclear.
Sprints and Midgets are the two original forms of open wheel race car in the United States; they have evolved considerably, but continue to be open wheel, front engine, rear wheel drive race cars for oval track racing. Some Sprint Car series (such as World of Outlaws) use cars with very large wings; others such as USAC require wingless cars. Sanctioning bodies running Sprint Car series include SCRA (West Coast), NARC (West Coast), and USAC (West Coast and Midwest both.) Midget car racing is sanctioned by USAC and by UMARA (Midwest), among others. There are many independent tracks that also run Sprint series, sometimes sharing rules with adjacent independents.