USAC patch The United States Auto Club (USAC) started it all for us.  Champ car racing and top wrenching August 17,1975.   See FASI Champ Car history.

 USAC was a very fundamental auto club that was formed in late 1955 when AAA would no longer sanction races as a result of tragic accident that killed 80 spectators at a LeMans race in '55.  They brought with them diversity centered around the Offenhauser 4 cyl.  You could run a naturally aspirated engine, a turbo flat crank V-8 Yunick Chevrolet, a turbo flat crank 8-cylinder Cosworth, or a turbo V-6 Buick.   USAC offered versatility and met its demise when all nine USAC officials died in a plane crash during their return trip from Trenton, NJ in 1979.  The president of the club, the 10th person of the group, was a little overwhelmed with work.

The end of USAC was imminent.  Championship Auto Race Teams (CART) was formed, the owners of teams with an opposing view of success was started.  Immediate opposite thinking for USAC teams was a bit much.  CART included unlimited money, an operating component for success, not ingenuity like USAC car owners.  It was harder to attract sponsorship for the old USAC teams.   In '94, the Indy Racing League (IRL) was formed.  A formidable foe with safer, standardized crash worthy cars.  The IRL has done well to this day.