There have been 1,052 players in MLB history born in Illinois (or at least that’s how many we know of). And of those players, the one with the most home runs is… Jim Thome with 612. But the player who’s second; the player who had the “record” prior to Thome was Gary Gaetti with 360.
Gary Gaetti homered in his MLB Debut (in his first at-bat) on September 20, 1981 for the Twins. As a rookie the following season he hit 25 long ones. He was a mainstay at the hot corner for the Twins in the 1980s, winning four Gold Gloves (1986-89) with two All-Star selections (1988-89). He was part of the 1987 World Champions (and was ALCS MVP). By the time the Twins won their second World Series in 1991, Gaetti was in California with the Angels. In 1995 at age 36 he had a renaissance for the Royals with 35 home runs and collected his lone career Silver Slugger before moving onto the Cardinals for the next few seasons.
After being released by the Birds in mid-1998, Gaetti arrived on the North Side where he hit 17 home runs in 150 games (in 1998-99). In that 1998 season, he was a teammate of both Mark McGwire (who hit 70 HR for the Cardinals) and Sammy Sosa (who hit 66 HR for the Cubs). He remains the last player age 40 or older to homer in a Cubs uniform (all 17 of his home runs with the Cubs came after he turned 40). Gaetti even made an appearance on the mound for the Cubs to close out what would end up a 21-8 rout at the hands of the Phillies on July 3, 1999 at the Vet. He allowed two runs, including a solo home run by Marlon Anderson and an RBI triple by Doug Glanville. Gaetti concluded his MLB career with five games for the Red Sox in 2000.
After his retirement as a player, Gaetti had some coaching gigs in the minors and majors. In 2012, when 50-year old Roger Clemens came back to make two starts for the independent Sugar Land Skeeters, Gary Gaetti was the manager, as he was three years later when 50-year old Rafael Palmeiro played a game for the Skeeters. Gaetti led the team to the Atlantic League championship in 2016.
Quite a career.