IndyCar's split history and its 2008 merger

The Indianapolis 500 is IndyCar's best-known race, held each year at the Indianapolis Motor Speedway. American open-wheel racing has had a difficult history, however. The championship peaked in the late 1980s and early 1990s under the sanctioning body CART, and drew international attention as former Formula 1 champions including Nigel Mansell, Emerson Fittipaldi and Mario Andretti competed in it.

The 1996 creation of the rival Indy Racing League split the sport and badly damaged the championship. CART, which rebranded as Champ Car, went into decline. By 2008, Champ Car was close to collapse, and the two series finally merged.

Today's IndyCar championship still has a reputation for spectacular racing. It uses a single-specification chassis and features road, street and traditional American oval circuits.