United SportsCar Championship

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, which was subsequently renamed as the IMSA SportsCar Championship in 2016. Rolex SA's Tudor brand was the title sponsor of the championship in 2014 and 2015, and WeatherTech has served as title sponsor since 2016.