In 1948 London Majors, considered one of the best teams in Intercounty history, not only won the Intercounty League championship, but the Canadian Baseball Congress Championship and the Can-Am North American championship of the National Baseball Congress beating the Fort Wayne, Indiana, General Electrics in a best-of-seven-game series played at Labatt Park, with such London stars as pitcher "Tireless" Tommy White, catcher Jack Fairs, short-stop/ fielder Russell (the Muscle) Evon, catcher Gil Robertson, infielder Don Cooper and rookie outfielder Joltin' Joe Bechard (the sole remaining member of the '48 Majors still alive is Jack Fairs).

The Majors won the opener on September 21, 1948, at Labatt Park when Joe Bechard's single in the 11th inning scored Johnny Lockington from second with the winning run in an 8–7 victory.

It was "the greatest display of clutch hitting ever seen in the local ball yard", wrote Free Press sports editor Jack Park.

Traditionally, one of the high points in the season of the London Majors is a game with the Toronto Maple Leafs on July 1 (Canada Day), which is usually followed by fireworks over the adjacent forks of the Thames River.

Previously, Alexander had been a star pitcher for a total of 14 seasons with the Homestead Grays and the Kansas City Monarchs of the Negro National League.

Other players on the 1975 Majors ballclub were: former Major League Baseball, left-handed pitcher Mike Kilkenny, a league all-star and 1975 Intercounty MVP; shortstop Dave Byers; all-star second-and-third baseman Barry Boughner; 1975 batting champion Larry Haggitt (.412); manager Roy McKay; coach John Ambrose; long-time coach-trainer Norm Aldridge (Aldridge has a City-owned baseball diamond named after him in northeast London called Norm Aldridge Field); Larry Wilson; pitcher Phil Schmidt; pitcher Rick Lindquist; Barry Fuller; Mike Fess; catcher Wayne (Dog) Fenlon; Brian Bell; captain Dave (Whitey) Lapthorne; infielder Mike Mitchell; infielder Rob Watral; John Marks; Alex McKay Jr; Jamie Hodge; John Gourley Jr.; pitcher Neal Ambrose; trainers Ed Loney and Bob Gilan; General Manager George Hall and batboy Jim McKay.

Kilkenny previously played for the Detroit Tigers (1969–1972), Oakland Athletics (1972), San Diego Padres (1972), and Cleveland Indians (1972–1973) during a five-season stint (1969–1973) in the Major Leagues.

On January 14, 2006, The London Free Press reported that the Majors had become an international organization with 11 scouts in Latin America, the U.S., Mexico, Italy and Japan.

Named to the second-all-star team in 2006 were outfielder Kevin Virtue, left-handed pitcher Erick Perez, designated hitter Chuck Roberts and manager Roop Chanderdat.

Rudy Vallejos, an outfielder with the 2006 London Majors, won the Intercounty Baseball League Rookie of the Year (Brian Kerr Memorial Trophy).

The 1937, tongue-and-groove clapboard Majors' clubhouse at Labatt Park, officially renamed "The Roy McKay Clubhouse" on August 1, 1996 (Roy McKay was born on August 1, 1933), by longtime Majors' owner-player Arden Eddie, was designated under Part IV of the Ontario Heritage Act in 1996—an initiative spearheaded by The Friends of Labatt Park—by amending the park's original (by-law) reasons for designation.

Owners of the team over the years have included Public Utilities Commission director Bill Farquharson, Clare Van Horne, ex-Major League Baseball player Frank Colman (1956–early 1960), jeweller Chester Pegg, sportswriter/ author Bob Ferguson (1963–64), Ted Earley, George Hall, Arden Eddie (1976-February, 2003) and the current co-owners of Scott Dart and Roop Chanderdat.

In 1955, Colman purchased the Majors in 1956 from Van Horne and co-founded the Eager Beaver Baseball Association with London sportsman Gordon Berryhill and Al Marshall.

On Canada Day of that same season, long-tenured and fan-favourite Major Cleveland Brownlee, who had played in the league since 2009 reached the 100 homerun plateau, in front of a near sold out crowd.