When the AAA withdrew from auto racing after the 1955 season — citing the 1955 Le Mans disaster and the death of Bill Vukovich at Indianapolis as contributing factors — the sport required a new governing body for its highest level. Indianapolis Motor Speedway owner Tony Hulman was instrumental in establishing USAC to fill that role. The new organisation assumed responsibility for what it termed championship auto racing, setting rules, car specifications, and officiating standards.
For its first two decades USAC was the unquestioned authority over Indy car racing. The National Championship it awarded drew the leading American open-wheel drivers and teams, and the Indianapolis 500 remained the centrepiece of the calendar.
By the late 1970s, tensions between USAC and the car owners who competed in its series had been building for several years. Owners were dissatisfied with USAC's negotiation of television rights, with prize money levels, and with what they regarded as favouritism toward certain technical regulations — particularly measures designed to keep the ageing Offenhauser engine competitive against the more modern Cosworth DFX, including boost-limiting devices and fuel restrictions.
A catastrophic plane crash on April 23, 1978 accelerated the restructuring of the sport. Eight USAC officials and the pilot were killed when their aircraft crashed during a thunderstorm 25 miles southeast of Indianapolis while returning from a race at Trenton Speedway in New Jersey. The loss of key personnel at a moment of institutional instability left USAC weakened at precisely the point when the owners were pressing for change.
In 1978, most car owners banded together to form Championship Auto Racing Teams (CART), which held its first race in 1979. USAC attempted to exclude all CART owners from the 1979 Indianapolis 500 but lost the resulting legal challenge before the race. Both organisations ran competing multi-race schedules in 1979. Indianapolis Motor Speedway president John Cooper facilitated the creation of the Championship Racing League in March 1980 as a joint USAC-CART body, but by mid-1980 USAC had been pressed to renounce the agreement in order to retain officiating rights at the Indianapolis 500. The two organisations subsequently settled into a degree of coexistence, with USAC continuing to sanction the Indy 500 while CART ran the rest of the season.
When the Indy Racing League split from CART in 1996, USAC served as the IRL's sanctioning body, including for the Indianapolis 500, until the IRL terminated the arrangement following officiating errors at the 1997 Indianapolis 500 and the 1997 True Value 500. Subsequent editions of the Indianapolis 500 have been sanctioned by the IRL itself, renamed the IndyCar Series in 2003.
USAC awarded a unified national championship through A.J. Foyt's seventh title in 1979, then resumed the award in 2010, with Bryan Clauson winning the inaugural revived championship. The current national championship aggregates points across the three national series: Silver Crown, sprint cars, and midget cars.
A prestigious individual milestone within USAC is the Triple Crown — earned when a driver claims all three national open-wheel championships (Silver Crown, sprint car, and midget car) in a single season. Only two drivers have accomplished this: Tony Stewart in 1995 and J.J. Yeley in 2003. Several other drivers have claimed each of the three championships at least once across multiple seasons, including Dave Darland, Jerry Coons Jr., Tracy Hines, Chris Windom, and Logan Seavey.
USAC's current competition portfolio centres on three national open-wheel championships. The Silver Crown Series, established in its current form in 1981 (having been known as the National Dirt Car Championship from 1971), is contested on both dirt and paved ovals. The National Sprint Car Championship and National Midget Championship are among the most historically significant grassroots open-wheel series in the United States. Regional divisions — including the USAC/CRA Sprint Car Series in California and Arizona, the Western States Midget Series, and various 360 sprint car series — extend the organisation's reach across the country.
Since 2022, USAC has expanded into road racing, sanctioning the USF Juniors, USF2000 Championship, and USF Pro 2000 Championship — a junior single-seater ladder feeding into the Indy NXT series — along with the Radical Sportscars North American Championships, the GT World Challenge America, and the Porsche Sprint Challenge North America.
USAC shaped the character of American open-wheel racing through its formative decades, providing governance during the period when Indy car racing grew into a nationally prominent sport. Its current role as a custodian of sprint, midget, and Silver Crown racing preserves a tradition of grassroots oval competition that predates CART and the IRL by many years, and which continues to serve as a development pathway for drivers aspiring to the highest levels of American motorsport.