Highlights in the long, complicated history of the open-wheel racing dispute:
1968: Turbines are effectively eliminated as a viable engine at Indianapolis. They, along with rear-engined cars imported from Europe, revolutionize the 500 in the '60s and cement two rifts: technology and innovation vs. tradition and affordability; and car owners vs. governing bodies.
1979: CART has its first season and goes head to head with USAC. USAC officials ban six CART teams from the 500; CART goes to court and wins its places in the 500, including one for eventual race winner Rick Mears.
1981: USAC ceases its open-wheel series. CART is left to rule American open-wheel racing for more than a decade.
1992: Jeff Gordon makes his Winston Cup debut. He came up through midgets and sprints but chose NASCAR instead of CART and the Indy 500. Open-wheel racing loses a top American talent to its stock car rival. Tony Stewart later follows Gordon's lead.
1995-96: Indianapolis Motor Speedway president Tony George announces formation of the Indy Racing League. He reserves 25 spots in the 1996 Indy 500 for IRL teams. CART rebels by staging its own Memorial Day weekend race, the U.S. 500, at Brooklyn, Mich. For the first time since 1981, there are two major American open-wheel series.
1997: The IRL starts its second season with a revamped chassis and engine package, making it so costly to run both a full CART season and the Indy 500 that no team has attempted it until 2000: Chip Ganassi's team, winner of four consecutive CART titles, announces it will run at the Brickyard with Jimmy Vasser and Juan Montoya.
_ Compiled by Jim Tomlin.