The team first appeared in a partial CART season in 1980, then returned in 1983 with rookie Al Unser Jr. Unser left after 1984, and in 1985 Galles fielded a Buick V-6 at the Indianapolis 500 with Pancho Carter winning the pole. In 1986 and 1987, the team became a primary supporter of the new Brabham-Honda engine pairing, with Geoff Brabham and Jeff MacPherson among their drivers. Unser Jr. returned to the team in 1988, now equipped with an Ilmor Chevrolet engine. In 1989, Unser came agonizingly close to winning the Indianapolis 500, finishing second after a late crash while dueling with Emerson Fittipaldi.
After the 1989 season, Galles merged with Maurice Kranes's operation, which brought Bobby Rahal and the Kraco sponsorship. The combined entity competed as Galles-Kraco Racing from 1990 to 1992. Unser won the 1990 CART championship with five victories, while Rahal served as the team's second driver. Rahal earned eleven second-place finishes for the team in the 1990-1991 period, won one race in 1991, and finished fourth in the 1990 championship and second in 1991, though he never claimed the title with the team.
In 1992, Rahal was replaced by veteran Danny Sullivan, and the team introduced its own in-house Galmer chassis. Unser won the 1992 Indianapolis 500 in a Galmer in what was the closest finish in race history at that time. Sullivan won at Long Beach in controversial circumstances — the two Galles cars tangled, sending Unser into the barriers while Sullivan continued to the checkered flag, creating lasting friction within the team. Despite the Galmer chassis's two victories, it was scrapped after just one season.
Unser and Sullivan retained their seats in 1993, joined by Kevin Cogan and Adrián Fernández for selected events. After a modest season, Unser departed for Penske Racing, and the team reverted to its Galles Racing name for 1994 with Fernández as the lone entry. Fernández remained for 1995 alongside Brazilian journeyman Marco Greco, with limited success.
In 1996, amid the CART-IRL split, Galles was one of few CART teams to enter the IRL's first Indianapolis 500, fielding Davy Jones, who finished second. Jones also ran a partial CART schedule, while rookie Eddie Lawson drove the full-time CART entry. The team moved to the IRL full-time in 1997 with rookie Kenny Bräck. Bräck left for A.J. Foyt Enterprises after one season, and the team briefly ceased operations before returning in 1999 with veteran Davey Hamilton.
In 2000, Al Unser Jr. rejoined as one of the first CART stars to switch to the IRL full-time. The team's final year was 2001, with Unser joined by rookies Didier André and Casey Mears. Rising costs ended the small operation after the season.
Across 22 years, Galles Racing drivers won 21 races — 18 by Al Unser Jr., two by Danny Sullivan, and one by Bobby Rahal. The team's 1990 CART championship and 1992 Indianapolis 500 victory represent its peak achievements. Unser Jr.'s 1989 near-miss at Indianapolis, when he crashed while leading with little more than a lap remaining, remains one of the most memorable finishes in race history and set up the team's subsequent run of success.