On February 21, 1948, NASCAR was formed by William France and Ed Otto. Both France and Otto took the first steps to regulate stock car racing because of many unscrupulous activities that had taken place in the early 1900s when stock car racing first became popular. They felt that stock car racing was not only unregulated, but unsafe, and many drivers were being taken advantage of.
The first unregulated stock car races took place on Daytona Beach. After NASCAR was formed, different divisions were created. One was the "modified" division. Also, the most popular race tracks at that time became the Charlotte Speedway and Occoneechee Speedway. The premiere track in 1949, was the Daytona Beach Road Course.
A "strictly stock" racing requirement was established. Any car that entered must have been made only of parts that were available to the general public through car dealers. For the car to be entered, it had to be one of at least 500 cars of the same model. Many of the NASCAR drivers would drive their own car to the competition and race the same car they drove there as a stock car!
At first, driving an "off the lot stock car" seemed like a good idea, but many of the drivers were getting hurt because the stock cars were being battered in ways that just did not occur in every day driving. The cars had to be modified simply in the interest of safety. Modern racing "stock" cars are stock in name only. They use a body template modeled after currently-available automobiles, but the chassis, running gear, and equipment have almost nothing to do with the original off the lot cars.
Modern stock cars are now racing machines built to a specific, strict set of regulations that state that the chassis and suspension must be "architecturally identical" on all stock cars. It's ironic that these regulations actually ensure that stock car racers are in many ways technologically less sophisticated than standard cars on the road.
For example, NASCAR, which is now the premier stock car organization in the US, requires carbureted engines in all of its racing cars, but fuel injection is now the universal standard in passenger cars. Engines must be near the same size and be designed so that each entrant has an equal chance of winning.
There are now several categories of stock car racing, each with slightly different rules, but the key intention of the cars is that they still look like production cars, but must have near-identical specifications underneath.
