The International Motor Sports Association (IMSA) is a North American sports car racing sanctioning body based in Daytona Beach, Florida, under the jurisdiction of the ACCUS arm of the FIA. It was started by John Bishop, a former executive director of SCCA (Sports Car Club of America), and his wife Peggy in 1969 with help from Bill France Sr. of NASCAR. Beginning in 2014, IMSA is the sanctioning body of the WeatherTech SportsCar Championship, the premier series resulting from the merger of Grand-Am Road Racing and the American Le Mans Series.
https://en.wikipedia.org/wiki/IMSA