The race was the first American Championship Car race won by a rear-engined car. Jim Clark and Team Lotus had finished second at the 1963 Indianapolis 500 after a controversy surrounding the lack of a black flag for winner Parnelli Jones, whose car was leaking oil. Colin Chapman and Team Lotus decided to return to Champ Car competition at Milwaukee and Trenton later in the year. The rear-engined Lotuses dominated practice and qualifying, breaking the track record by over a second. In the race, Clark led all 200 laps and lapped the entire field, save for second place A. J. Foyt. Clark's teammate Dan Gurney finished third, battling a misfire.