Originally a minor league known as the Western League, the league later developed into a major league after the American Association disbanded. In its early history, the Western League struggled until 1894, when Ban Johnson became the president of the league. Johnson led the Western League into major league status and soon became the president of the newly renamed American League. Babe Ruth, noted as one of the most prolific hitters in Major League Baseball history, spent the majority of his career in the American League. The American League has one notable difference over the National League, and that is the designated hitter rule. Under the rule, a team may use a batter in its lineup who is not in the field defensively, compared to the old rule that made it mandatory for the pitcher to hit.
President Calvin Coolidge and Washington Senators pitcher Walter Johnson shake hands following the Senators’ 1924 championship.
In 1977, the league expanded to fourteen teams, when the Seattle Mariners and Toronto Blue Jays were enfranchised. The Toronto franchise was the AL’s attempt to compete with the National League’s Montreal Expos while the Mariners were added in an attempt to settle a pending $90 million lawsuit against the league by the city of Seattle over the quick departure of the Pilots in 1970.
Until the late 1970s, league umpires working behind home plate wore large, balloon-style chest protectors worn outside the shirt or coat, while their brethren in the National League wore chest protectors inside the shirt or coat. In 1977, new umpires (including Steve Palermo) had to wear the inside chest protector, although those on staff wearing the outside protector could continue to do so. Most umpires made the switch to the inside protector, led by Don Denkinger in 1975 and Jim Evans two years later, although several did not, including Bill Haller, Lou DiMuro, George Maloney and Jerry Neudecker, who became the last Major League umpire to use the outside protector in 1985.
In 1994, the league, along with the National League, reorganized again, into three divisions (East, West, and Central) and added a third round to the playoffs in the form of the League Divisional Series, with the best second-place team advancing to the playoffs as a wild-card team, in addition to the three divisional champions. In 1998, the newly franchised Tampa Bay Devil Rays joined the league, and the Arizona Diamondbacks joined the National League: i.e., each league each added a fifteenth team. An odd number of teams per league meant that at least one team in each league would have to be idle on any given day, or alternatively that odd team out would have had to play an interleague game against its counterpart in the other league. The initial plan was to have 3 five-team divisions per league with interleague play year-round—possibly as many as 30 interleague games per team each year. For various reasons, it soon seemed more practical to have an even number of teams in both leagues. So, the Milwaukee Brewers agreed to change leagues, moving from the AL Central to the NL Central. (This was the first time since the 1890s that a team had moved from one major league to another.) At the same time, the Detroit Tigers shifted over to the AL Central,making room for the Devil Rays in the East.) After the Houston Astros move to the AL West in 2013, the leagues will once again each have 15 teams.
For the first 96 years, American League teams faced their National League counterparts only in exhibition games or in the World Series. Beginning in 1997, interleague games have been played during the regular season and count in the standings. As part of the agreement instituting interleague play, the designated-hitter rule is used only in games where the American League team is the home team. Through the 2011 season, the Yankees have won the most American League pennants (40), followed by the Athletics (15), Red Sox (12), and Tigers (10). Likewise, the Yankees have also won the most World Series (27), with the Athletics second in the American League with nine, the Red Sox third with seven, and the Tigers fourth with four.