On July 12, 1996, longtime Minnesota Twins star and future Hall of Famer Kirby Puckett announces his retirement due to glaucoma in his right eye. Over a 12-year career, the popular Puckett batted .318 with 207 home runs and 1,085 RBIs. He also helped the Twins to World Championships in 1987 and 1991.

On July 12, 1979, the Chicago White Sox stage "Disco Demolition Night" at Comiskey Park. After the Sox lose the first game to the Detroit Tigers, 4-1, thousands of fans run onto the field. After a delay of more than an hour, the umpires rule the field unplayable, causing the ChiSox to forfeit the second game.

On July 12, 1949, Larry Doby of the Cleveland Indians and Jackie Robinson, Roy Campanella, and Don Newcombe of the Brooklyn Dodgers become the first African Americans to play in an All-Star Game. The four black stars appear in the historic game at Ebbets Field, where the American League defeats the National League, 11-7.

On July 12, 1921, Babe Ruth of the New York Yankees hits his 137th career home run, moving past fellow Hall of Famer Roger Connor on the all-time list. Connor hit 136 home runs during his career-all during the 19th century.

On July 12, 1901, future Hall of Famer Cy Young of the Boston Beaneaters records the 300th win of his career. Young defeats the Philadelphia Aís, 5-3. Young will win 211 more games, for a total of 511, the most in major league history.