List of defunct and relocated Major League Baseball teams
Throughout the history of Major League Baseball, numerous franchises have moved or become defunct. Many of these franchises played in the National League (NL) and the American League (AL), the two existing major leagues, but other franchises played in one of the eleven major leagues that ultimately went defunct. The classification of the major leagues is based on Major League Baseball's recognition of historical leagues. Major league baseball emerged in the 1870s, and four major leagues, including the NL, played at least one season of baseball in the nineteenth century . During this period, dozens of franchises were founded, but most went defunct, leaving just twelve NL franchises by the 1892 season. After four of the twelve NL franchises went defunct following the 1899 season, the American League emerged in 1901 with several newly founded franchises. The Federal League (FL) challenged the primacy of the American League and the National League for two seasons, but the FL and all of its franchises went defunct after the 1915 season. Numerous Negro leagues operated during the first half of the twentieth century; seven leagues that operated from 1920 to 1948 were later recognized  as major leagues by Major League Baseball. Outside of the Negro leagues, no major league franchises relocated for several years after 1915, until the Boston Braves moved to Milwaukee following the 1952 season. Several teams relocated over the next twenty years, often moving to the Western or Southern United States. After a period of over thirty years with no relocation, the Montreal Expos became the Washington Nationals in 2005. List of defunct and relocated major league franchises since 1892. National, American, and Federal League franchises. These franchises played in the National League, the American League, or the Federal League after  the 1891 season and either went defunct or relocated. Some franchises appear more than once in the table; for example, the Braves franchise appears twice because they moved to Milwaukee in 1952 and to Atlanta in 1965. ! Team ! League ! First ! Last ! Seasons ! Post-change Status ! Current Status ! P ! WS ! class=unsortable|Reason for move/disbandment ! class=unsortable|Ref