first answer gets 10 points
It was started by Bill France in the 1940's. That's all I know.
It was started in the 1940s when a bunch of people who ran moonshine got together and decided to start having races. Their cars were souped up to help them run from the police when running shine, and they decided to get together and organize races.
Bill France started NASCAR as a traveling race league in 1949. It was first made popular in the southeastern United States. Races were held two to three times a week, sometimes on the same day/night at different tracks. Most races were on local short tracks, some dirt, some paved. A few investors built "super speedways" for Nascar to compete on. Darlington was the first of these. A couple of years after Bill France started NASCAR, John Marcam met with him and started ARCA (Automobile Racing Club of America) to compete in the mid-west. To see where NASCAR was 20 years ago, attend an ARCA race.
Racing itself started with bootlegging and moonshine when moonshiners would soup up their cars to get away from the cops during prohibition in the 20's and 30's. That is where the France family got the concept and in the 40's nascar was born in Daytona Beach Florida.