IMSA

The IMSA SportsCar Championship, currently known as the IMSA WeatherTech SportsCar Championship under sponsorship, is a sports car racing series based in the United States and Canada and organized by the International Motor Sports Association (IMSA). It is considered the pinnacle of sports car racing in North America, attracting top-tier manufacturers, teams and drivers. The championship features prototypes and GT cars competing across various classes and consists of both long-distance endurance races and shorter sprint races.

The series traces its roots to the IMSA GT Championship, which began in 1971 and ran until 1998. From the late 1990s until 2013, top-level sports car racing in North America was split between the high-tech American Le Mans Series and the low-cost Rolex Sports Car Series. These two series were merged in 2014 to form the United SportsCar Championship.