1876 The National League of Professional Baseball Clubs of Major League Baseball is formed.
1914 Baseball legend Babe Ruth makes his major league debut with the Red Sox
1939 Major League Baseball's Lou Gehrig, the legendary Yankee first baseman known as "The Iron Horse", ends his 2130 consecutive games played streak after contracting amyotrophic lateral sclerosis. The record will stand for 56 years before Cal Ripken, Jr. plays 2131 consecutive games.
1951 "Shot Heard 'Round the World" One of the greatest moments in Major League Baseball history occurs when the New York Giants Bobby Thomson hits a game winning home run in the bottom of the ninth inning off of the Brooklyn Dodgers pitcher Ralph Branca, to win the National League pennant after being down 14 games.
1981 Major League Baseball goes on strike, forcing the cancellation of 38 percent of the schedule.
1981 Major League Baseball resumes from strike with the All-Star Game in Cleveland's Municipal Stadium.
1984 The longest game in Major League Baseball history begins at 7:30 PM between the Milwaukee Brewers and the Chicago White Sox. The game will be played over the course of 2 days, lasting 25 innings, with a total time of 8 hours and 6 minutes.
1986 The New York Mets win the Major League Baseball World Series, beating the Boston Red Sox in 7 games.
1994 Major League Baseball players go on strike, canceling the World Series.
2003 The Florida Marlins defeat the Chicago Cubs in Game 6 of Major League Baseball's National League Championship Series; the game is remembered for Cubs fan Steve Bartman interfering with a foul ball which could have helped Chicago win the game and the series. The Marlins go on to win the World Series.
2004 The New York Yankees defeat the Boston Red Sox 19-8 in Game 3 of Major League Baseball's American League Championship Series. The game, which pushed the Yankees to a 3 games to 0 series lead, sets a record for longest 9 inning baseball game.
2004 The Boston Red Sox defeat the New York Yankees 10-3 in Game 7 of the Major League Baseball's American League Championship Series to win the series 4 games to 3. The Boston Red Sox become the first team in baseball history to come back from a 3-0 deficit to win a series.