The American League began play in 1901 as the “Junior Circuit” to the established National League. Like the older league, the AL was composed of 8 teams: Baltimore, Boston, Chicago, Cleveland, Detroit, Milwaukee, Philadelphia, and Washington. It remained an 8-team league for 60 years, and the original franchises are all in the league today, although 4 of them are no longer in their original cities.

The American League franchise moves are a little more confusing than those of the National League: No National League teams moved until team nicknames were well established, and with the exception of the most recent move in 2005, teams kept their names when they moved. By contrast, several of the American League franchise shifts involved complete name changes and the assumption of names previously used by other franchises.

1902 and 1903: The Milwaukee and Baltimore Franchises Move Early

The Milwaukee Brewers played only one season in Milwaukee before departing for St. Louis in 1902, where they played as the Browns for 52 years before moving to Baltimore in 1954 to become the Orioles.

Meanwhile, the Baltimore Orioles franchise that was a charter member of the American League moved to New York in 1903. In New York, the team was known as the Highlanders until 1913, when it dropped that name in favor of the New York Yankees.

1954 and 1955: St. Louis and Philadelphia Lose Their AL Teams

With some additional nickname changes, the 8 American League teams remained in place from 1903 until the Browns’ move to Baltimore in 1954. Another change came in the following year, when the Philadelphia Athletics moved to Kansas City.

Browns Move to Baltimore: Despite usually mediocre on-field results, the St. Louis Browns were for 20 years considerably more popular than the National League’s Cardinals, with whom they shared their stadium, Sportsman’s Park. In 1926, however, the Cardinals beat the Yankees in the World Series, and the St. Louis fans embraced the Cardinals at the expense of the Browns.

The Browns regained some popularity in the early 1950s under their new owner, the showman Bill Veeck, but when the Cardinals were sold to brewing giant Anheuser-Busch, Veeck sold the Browns to a group that moved them to Baltimore. They began a new life as the Baltimore Orioles in the 1954 season.

Athletics Move to Kansas City: The Athletics were managed by the legendary Connie Mack for the first 50 years of their existence and reached the World Series 8 times through 1931. But by the 1950s, the team had posted consistently poor results for 2 decades, and the owners decided to move west to Kansas City for the 1955 season.