The September 11 terrorist attacks on New York and Washington, D.C. pushed the end of the regular-season from September 30 to October 7. Because of the attack, the World Series was not completed until November 4. The 2001 World Series was the first World Series to end in November.
MLB used an unbalanced schedule for the first time since 1992 in the National League and 1977 in the American. In all divisions except the NL Central and AL West each team played each of the other four teams in the same division 19 times. In the NL Central division foes met 16 or 17 times per season and in the AL West there were 19 or 20 games between each division foe.
This season was memorable for the Seattle Mariners tying the Major League regular season record of 116 wins, Barry Bonds breaking Mark McGwire's single-season home run record, and baseball's patriotic return after a week's worth of games being postponed due to the 9/11 terrorist attacks.