The following is a timeline of franchise evolution inMajor League Baseball (MLB).

Source:The Baseball Encyclopedia (10 ed.). Macmillan General Reference. 1996.ISBN 978-0028608150.

Note: Team names are given here according to the convention used byThe Baseball Encyclopedia, which regularized them into the familiar form of modern team names. However, most teams in the early period had no name, aside from that of the club (as in "Hartford Base Ball Club" or "Athletic Base Ball Club of Philadelphia"), and nicknames like "Beaneaters," "Perfectos" and the many allusions to uniform colors were inventions by the florid sportswriters of the day.^[1]

TheNational Association of Base Ball Players (NABBP) was the first organization to govern baseball. The succeedingNational Association of Professional Base Ball Players (NA) was then established as the firstprofessional baseball league. In 1876 six clubs from the NA and two independents joined to create theNational League (NL). In subsequent years, the following major leagues competed against the NL, but all eventually folded:

• American Association (AA) (1882–1891) – eight franchises transferred to the NL, both during and after the AA's existence.
• Union Association (UA) (1884) – only one franchise joined the NL after the UA disbanded.
• Players' League (PL) (1890) – none of its franchises joined the NL.

In 1900 the minor leagueWestern League renamed itself theAmerican League (AL). All of the 1899 Western League teams were a part of the transformation with the Saint Paul Apostles moving to Chicago to play as the White Stockings. In 1901 the AL declared itself a major league. For its inaugural major league season the AL dropped its teams in Indianapolis, Buffalo and Minneapolis and replaced them with franchises in Boston, Philadelphia, and Baltimore. The Kansas City Blues moved to Washington D.C. to play as the Senators.

Another major league competitor was theFederal League (FL) (1914–1915). However, none of its teams joined either the NL or AL after it disbanded.

In 2020, Major League Baseball designated the following sevenNegro leagues from 1920–1948 as major leagues:^[2]

• Negro National League I (NNL I) (1920–1931)
• Eastern Colored League (ECL) (1923–1928)
• American Negro League (ANL) (1929)
• East–West League (EWL) (1932)
• Negro Southern League (NSL) (1932)
• Negro National League II (NNL II) (1933–1948)
• Negro American League (NAL) (1937–1948)

The first line is the formation of theNational League (NL) in 1876, and the second is the transformation of theAmerican League (AL) to a major league in 1901. The third line is the beginning of the expansion era in 1961. The fourth line marks the legal merger of the American and National Leagues into a singleMajor League Baseball in 2000.

World Series championships are shown with a "•", National League Pennants before the World Series are shown with a "^", and American League Pennants before the World Series are shown with a "#". No World Series was played in 1904, so the pennant winners for each league are indicated. Due to the1994–95 Major League Baseball strike, there were no pennant or World Series winners in 1994, so this year is left blank.

• Prior to 1876, only teams from the National Association (NA) that established the NL are shown.
• Between 1876 and 1901, in addition to the NL teams, only American Association (AA) and Union Association (UA) teams that eventually joined the NL are shown. No teams from the Players' League (PL) are shown.
• After 1901, only AL and NL teams are shown. No teams from the Federal League (FL) nor the seven Negro leagues are shown.

The NL was established with eight teams.

• The New York Mutuals and Philadelphia Athletics were expelled.
• The Hartford Dark Blues moved toBrooklyn and became theBrooklyn Hartfords.

• The Brooklyn Hartfords, Louisville Grays, and St. Louis Brown Stockings folded.
• The Indianapolis Blues, Milwaukee Grays, and Providence Grays joined.

• The Indianapolis Blues and Milwaukee Grays folded.
• TheBuffalo Bisons,Cleveland Blues,Syracuse Stars, andTroy Trojans joined.

• The Syracuse Stars folded.
• The Cincinnati Reds disbanded and were replaced by theCincinnati Stars.
• TheWorcester Worcesters joined.

• The Cincinnati Stars were expelled because they refused to sign a league-wide pledge to ban alcohol at ballparks.
• TheDetroit Wolverines joined.

TheAA was established with six teams.

• The Troy Trojans and Worcester Worcesters folded.
• TheNew York Gothams andPhiladelphia Quakers joined the NL.
• TheColumbus Buckeyes andNew York Metropolitans joined the AA.
• The Boston Red Caps became theBoston Beaneaters.
• The new St. Louis Brown Stockings became theSt. Louis Browns.

• The UA was established with eight teams.
• TheBrooklyn Atlantics,Indianapolis Hoosiers,Toledo Blue Stockings, andWashington Nationals joined the AA.
• TheAltoona Mountain Citys folded early-season and were replaced by theKansas City Cowboys.
• TheWashington Nationals from the AA folded mid-season and were replaced by theRichmond Virginians from Minor League Baseball.
• ThePhiladelphia Keystones folded mid-season and were replaced by theWilmington Quicksteps from Minor League Baseball. The Quicksteps then folded late-season and were replaced by theMilwaukee Brewers, also from Minor League Baseball.
• The Chicago Browns moved to Pittsburgh and became thePittsburgh Stogies, who folded late-season and were replaced by theSt. Paul Saints.

• The UA disbanded.
• The St. Louis Maroons from the UA joined the NL.
• The Cleveland Blues, Columbus Buckeyes, Indianapolis Hoosiers, and Toledo Blue Stockings folded.
• The Richmond Virginians returned to Minor League Baseball.
• The New York Gothams became theNew York Giants.
• The Brooklyn Atlantics became theBrooklyn Grays.
• The Louisville Eclipse became theLouisville Colonels.

• The Buffalo Bisons transferred toMinor League Baseball.
• The Providence Grays folded.
• A newKansas City Cowboys andWashington Nationals joined the NL.

• The Kansas City Cowboys folded.
• The St. Louis Maroons moved toIndianapolis and became theIndianapolis Hoosiers.
• The Pittsburgh Alleghenys transferred to the NL.
• A newCleveland Blues joined the AA.

• The Brooklyn Grays became theBrooklyn Bridegrooms.
• The New York Metropolitans folded.
• A newKansas City Cowboys joined the AA.

• The Detroit Wolverines folded.
• The Cleveland Blues transferred to the NL and became theCleveland Spiders.
• TheColumbus Solons joined the AA.

• The PL was established with eight teams.
• The Chicago White Stockings became theChicago Colts.
• The Philadelphia Quakers became thePhiladelphia Phillies.
• The Brooklyn Bridegrooms transferred to the NL.
• The Cincinnati Red Stockings transferred to the NL and became theCincinnati Reds.
• The Indianapolis Hoosiers, Kansas City Cowboys, and Washington Nationals folded.
• The Baltimore Orioles transferred to Minor League Baseball and were replaced by theBrooklyn Gladiators. The Brooklyn Gladiators then folded mid-season, and the Baltimore Orioles returned to the AA to finish the season.
• TheRochester Broncos, a newSyracuse Stars, and theToledo Maumees joined the AA.

• The PL disbanded.
• The Brooklyn Bridegrooms became theBrooklyn Grooms.
• The Pittsburgh Alleghenys became thePittsburgh Pirates.
• The Boston Reds from the PL joined the AA.
• The Philadelphia Athletics from the AA were expelled and replaced by the new Philadelphia Athletics from the PL.
• TheCincinnati Kelly's Killers joined the AA. They then folded mid-season and were replaced by the newMilwaukee Brewers from independent leagueWestern Association.
• TheWashington Statesmen joined the AA.

• The AA folded.
• The Baltimore Orioles, Louisville Colonels, St. Louis Browns, and Washington Statesmen (all from the AA) joined the NL.
• The Washington Statesmen became theWashington Senators.

The Brooklyn Grooms became the Brooklyn Bridegrooms again.

The Chicago Colts became theChicago Orphans.

• The Brooklyn Bridegrooms became theBrooklyn Superbas.
• The St. Louis Browns became theSt. Louis Perfectos.

• The Baltimore Orioles, Cleveland Spiders, Louisville Colonels, and Washington Senators folded.
• The St. Louis Perfectos became theSt. Louis Cardinals.

The AL was established with eight teams.

• The Milwaukee Brewers moved to St. Louis and became theSt. Louis Browns.
• The Cleveland Blues became theCleveland Bronchos

• The NL and AL signed the National Agreement which formed theNational Baseball Commission. They then promoted cooperation between the NL and AL.
• The newBaltimore Orioles folded.
• TheNew York Highlanders joined the AL.
• The Cleveland Bronchos became theCleveland Naps.
• The Chicago Orphans became theChicago Cubs.
• FirstWorld Series played between the AL and NL champions.

The Chicago White Stockings became theChicago White Sox.

The Boston Beaneaters became theBoston Doves.

The Boston Americans became theBoston Red Sox.

• The Boston Doves became theBoston Rustlers.
• The Brooklyn Superbas became theBrooklyn Trolley Dodgers.

The Boston Rustlers became theBoston Braves.

• The New York Highlanders became theNew York Yankees.
• The Brooklyn Trolley Dodgers became theBrooklyn Dodgers.

• TheFederal League (FL) declared itself as a "third major league" with its own eight teams, and competed with the NL and AL.
• The Brooklyn Dodgers became theBrooklyn Robins.

• The Cleveland Naps became theCleveland Indians.
• The Buffalo Buffeds became theBuffalo Blues.
• The Chicago Federals became theChicago Whales.
• The new Indianapolis Hoosiers moved toNewark, New Jersey, and became theNewark Peppers.

The FL folded prior to the season.

TheNNL was established with eight teams, the first black baseball league to be designated a major league.

• Following the fallout from the1919 Black Sox Scandal, in November 1920, the National Baseball Commission was replaced by theCommissioner of Baseball, who acts as the chief executive officer of major and minor leagues.^[3][4]
• TheDayton Marcos departed the NNL as an independent team.
• A newColumbus Buckeyes joined the NNL.
• The Cuban Stars became theCincinnati Cuban Stars.

• TheChicago Giants andColumbus Buckeyes folded.
• TheCleveland Tate Stars andPittsburgh Keystones joined the NNL.
• The Cincinnati Cuban Stars became theCuban Stars again.
• The St. Louis Giants became theSt. Louis Stars.

• TheECL was established with six teams.
• ThePittsburgh Keystones folded.
• TheMilwaukee Bears joined the NNL.
• TheCleveland Tate Stars departed from the NNL as an independent team and were replaced by theToledo Tigers. The Toledo Tigers then folded mid-season, and the Cleveland Tate Stars returned to the NNL as an associate member to finish the season.

• TheMilwaukee Bears folded.
• TheBirmingham Black Barons andCleveland Browns joined the NNL.
• TheHarrisburg Giants andWashington Potomacs joined the ECL.
• TheIndianapolis ABCs temporarily dropped out for the season in June and were replaced by theMemphis Red Sox.

• TheCleveland Browns folded.
• TheIndianapolis ABCs returned to the NNL.
• The Washington Potomacs moved toWilmington, Delaware and became theWilmington Potomacs and then folded mid-season.

• TheCleveland Elites joined the NNL and folded mid-season.
• TheDayton Marcos returned to the NNL and departed mid-season as an independent team.
• TheNewark Stars joined the ECL and folded mid-season.
• TheBirmingham Black Barons andMemphis Red Sox departed the NNL and joined Minor League Baseball'sNegro Southern League (NSL).

• TheIndianapolis ABCs folded.
• TheBirmingham Black Barons andMemphis Red Sox returned to the NNL.
• TheCleveland Hornets joined the NNL.

• TheCleveland Hornets folded.
• TheBrooklyn Royal Giants,Harrisburg Giants, andHilldale Club withdrew from the ECL as independent teams.
• TheCleveland Tigers joined the NNL.
• ThePhiladelphia Tigers joined the ECL.
• The ECL then disbanded mid-season.

• TheANL was established with six teams. Five of those teams were from the ECL. The independentHomestead Grays also joined the ANL.
• TheCleveland Tigers folded.
• ThePhiladelphia Tigers folded.

• TheAtlantic City Bacharach Giants and theCuban Stars from the ANL folded.
• TheBaltimore Black Sox,Hilldale Club,Homestead Grays, andNew York Lincoln Giants became independent teams.
• The ANL disbanded.
• TheLouisville Black Caps andNashville Elite Giants joined the NNL.

• TheCuban Stars folded.
• TheBirmingham Black Barons,Memphis Red Sox, andNashville Elite Giants departed theNNL and joined theNSL.
• TheKansas City Monarchs departed the NNL as an independent team (though remains looselyassociated with the league).
• TheCleveland Cubs and a newIndianapolis ABCs joined the NNL.
• The Chicago American Giants became theChicago Columbia Giants.
• The Louisville Black Caps became theLouisville White Sox.
• The NNL disbanded mid-season; although, teams continued to play each other as independent teams.

• The Brooklyn Robins became theBrooklyn Dodgers again.
• The Detroit Stars and St. Louis Stars folded.
• TheCleveland Cubs moved back toNashville, Tennessee and became theNashville Elite Giants again.
• TheEWL was established with eight teams. Three of those teams, theBaltimore Black Sox,Hilldale Club, andHomestead Grays were from the ANL.
• The NSL was considered a major league for the season with 10 teams. Five of those teams, theBirmingham Black Barons,Chicago Columbia Giants,Indianapolis ABCs,Memphis Red Sox, andNashville Elite Giants were from the NNL.
• The Chicago Columbia Giants became theChicago American Giants again.
• TheNewark Browns departed mid-season as an independent team.

• The Little Rock Grays and Columbus Turf Club folded.
• The Atlanta Black Crackers and Birmingham Black Barons withdrew as independent teams.
• The NSL was demoted to minor league status.
• The Cleveland Stars, Detroit Wolves, Hilldale Club, and Newark Browns folded.
• Pollock's Cuban Stars and the Washington Pilots withdrew as independent teams.
• The Baltimore Black Sox became theBaltimore Sox.
• The EWL disbanded.
• The secondNNL was established with 7 teams. Five of those teams, the Baltimore Sox,Chicago American Giants,Homestead Grays,Indianapolis ABCs, andNashville Elite Giants were from the NSL or EWL.
• ThePittsburgh Crawfords joined the NNL.
• The Indianapolis ABCs moved mid-season toDetroit, Michigan and became theDetroit Stars.
• TheColumbus Blue Birds joined the NNL. The team disbanded and merged with the independentAkron Black Tyrites after the first half of the split season. The Akron Black Tyrites joined the NNL in place of the Columbus Blue Birds as the Akron Grays before they moved toCleveland, Ohio and became theCleveland Giants for one game.

• TheCleveland Giants andDetroit Stars folded.
• TheHomestead Grays withdrew as an independent team.
• TheCleveland Red Sox,Newark Dodgers,Philadelphia Bacharach Giants, andPhiladelphia Stars joined the NNL.
• The Baltimore Sox became theBaltimore Black Sox again.

• TheCleveland Red Sox folded.
• TheBaltimore Black Sox andPhiladelphia Bacharach Giants withdrew as independent teams.
• TheBrooklyn Eagles andNew York Cubans joined the NNL.
• TheHomestead Grays returned to the NNL.
• The Nashville Elite Giants moved toColumbus, Ohio and became theColumbus Elite Giants.

• The Boston Braves became theBoston Bees.
• TheChicago American Giants withdrew.
• The Brooklyn Eagles and Newark Dodgers merged and became theNewark Eagles.
• TheNew York Black Yankees joined the NNL.
• The Columbus Elite Giants moved toWashington, D.C. and became the Washington Elite Giants.

• TheNAL was established with eight teams. Four of those teams, theBirmingham Black Barons,Chicago American Giants,Kansas City Monarchs, andMemphis Red Sox were previously from the NSL or the first NNL.
• TheNew York Cubans withdrew.

• TheCincinnati Tigers, the newDetroit Stars, theIndianapolis Athletics, and the newSt. Louis Stars folded.
• TheAtlanta Black Crackers, a newIndianapolis ABCs, and theJacksonville Red Caps joined the NAL.
• TheWashington Black Senators joined the NNL.
• The Washington Elite Giants moved toBaltimore, Maryland and became theBaltimore Elite Giants.

• TheWashington Black Senators folded.
• TheBirmingham Black Barons withdrew.
• TheNew York Cubans returned to the NNL.
• TheIndianapolis ABCs moved toSt. Louis, Missouri and became theSt. Louis Stars.
• The Atlanta Black Crackers moved toIndianapolis, Indiana and became theIndianapolis ABCs.
• The Jacksonville Red Caps moved toCleveland, Ohio and became theCleveland Bears.
• The Pittsburgh Crawfords moved toToledo, Ohio and became theToledo Crawfords.
• The Toledo Crawfords withdrew and joined the NAL mid-season.

• TheIndianapolis ABCs folded.
• TheBirmingham Black Barons returned to the NAL.
• The St. Louis Stars split their home games betweenSt. Louis, Missouri andNew Orleans, Louisiana and became theSt. Louis–New Orleans Stars.
• The Toledo Crawfords split their home games betweenToledo, Ohio andIndianapolis, Indiana and became theToledo–Indianapolis Crawfords.^[5]

• The Boston Bees became theBoston Braves again.
• TheToledo–Indianapolis Crawfords folded.
• The Cleveland Bears moved back toJacksonville, Florida and became theJacksonville Red Caps again.

• ThePhiladelphia Phillies became the Philadelphia Phils.
• TheSt. Louis–New Orleans Stars disbanded.
• TheCincinnati–Cleveland Buckeyes joined the NAL.
• TheJacksonville Red Caps departed mid-season.

• ThePhiladelphia Phils became the Philadelphia Phillies again.
• The St. Louis–New Orleans Stars reformed and joined the NNL as theHarrisburg–St. Louis Stars, since they moved toHarrisburg, Pennsylvania; although, they kept the St. Louis moniker as a part of their name. The team proceeded to withdraw in July to barnstorm, and then they folded.
• The Cincinnati–Cleveland Buckeyes leftCincinnati, Ohio and became theCleveland Buckeyes.
• TheCincinnati Clowns joined the NAL.

The Cincinnati Clowns split their home games betweenCincinnati, Ohio andIndianapolis, Indiana and became theCincinnati–Indianapolis Clowns, though would play more games in Indianapolis beginning in 1946.

TheBrooklyn Dodgers,Cleveland Indians, andSt. Louis Brownsintegrated.

• The Cincinnati–Indianapolis Clowns stopped playing inCincinnati, Ohio and permanently played inIndianapolis, Indiana and became theIndianapolis Clowns.

• The New York Black Yankees folded.
• Due to the ongoing process ofintegration, theNAL lost its major league status.
• TheNNL folded.
• All of the NNL teams, except for the newly independentHomestead Grays joined the NAL.
• TheNew York Giantsintegrated.

TheBoston Bravesintegrated.

TheChicago White Soxintegrated.

• The Boston Braves moved to Milwaukee and became theMilwaukee Braves.
• The Cincinnati Reds became theCincinnati Redlegs.
• TheChicago Cubs,Philadelphia Athletics, andPittsburgh Piratesintegrated.

• The St. Louis Browns moved to Baltimore and became theBaltimore Orioles.
• TheCincinnati Redlegs,St. Louis Cardinals, andWashington Senatorsintegrated.

• The Philadelphia Athletics moved toKansas City, Missouri, and became theKansas City Athletics.
• TheNew York Yankeesintegrated.

ThePhiladelphia Philliesintegrated.

• The Brooklyn Dodgers moved to Los Angeles and became theLos Angeles Dodgers.
• The New York Giants moved to San Francisco and became theSan Francisco Giants.
• TheDetroit Tigersintegrated.

• The Cincinnati Redlegs became the Cincinnati Reds again.
• TheBoston Red Soxintegrated.

• The Washington Senators moved to theMinneapolis–Saint Paul area and became theMinnesota Twins.
• TheLos Angeles Angels and a newWashington Senators joined the AL.

• TheHouston Colt .45s andNew York Mets joined the NL.

• The Houston Colt .45s became theHouston Astros.
• The Los Angeles Angels became theCalifornia Angels on September 2, 1965, with 28 games left in the season.

The Milwaukee Braves moved toAtlanta and became theAtlanta Braves.

The Kansas City Athletics moved toOakland, California, and became theOakland Athletics.

• TheKansas City Royals andSeattle Pilots joined the AL.
• TheMontreal Expos andSan Diego Padres joined the NL.
• The two leagues each realigned into two six-team divisions

The Seattle Pilots moved toMilwaukee and became theMilwaukee Brewers.

• The Washington Senators moved toArlington, Texas, in theDallas–Fort Worth metroplex and became theTexas Rangers.
• The Texas Rangers and Milwaukee Brewers switched divisions.

• TheSeattle Mariners joined the AL West.
• TheToronto Blue Jays joined the AL East.

• TheColorado Rockies joined the NL West.
• TheFlorida Marlins joined the NL East.

The two leagues realigned to three divisions in each to accommodate an expanded postseason format with awild card team (although this new playoff format would not be fully implemented until 1995 due to awork stoppage):

• TheAL Central was formed with the Cleveland Indians and Milwaukee Brewers transferring from the AL East, and the Chicago White Sox, Kansas City Royals, and Minnesota Twins transferring from the AL West.
• TheNL Central was formed with the Chicago Cubs, Pittsburgh Pirates, and St. Louis Cardinals transferring from the NL East, and the Cincinnati Reds and Houston Astros transferring from the NL West.
• The Atlanta Braves transferred to the NL East.

The California Angels became theAnaheim Angels.

• TheArizona Diamondbacks joined the NL West.
• TheTampa Bay Devil Rays joined the AL East.
• The Detroit Tigers transferred to the AL Central.
• To continue intraleague-only play throughout most of the season, the Milwaukee Brewers transferred to the NL Central so both leagues would have an even number of teams.

• The AL and NL merged and formedMajor League Baseball (MLB).

In 2001, MLB team owners voted 28–2 to eliminate two teams, theMinnesota Twins and theMontreal Expos for the 2002 season. In this realignment:

• Texas Rangers would move to theAL Central
• Arizona Diamondbacks would move to theAL West
• Pittsburgh Pirates would move to theNL East

By December 2001, this plan was scrapped; both teams would be retained for the following season.

• The Montreal Expos moved to Washington, D.C. and became theWashington Nationals.
• The Anaheim Angels became theLos Angeles Angels of Anaheim.

The Tampa Bay Devil Rays became theTampa Bay Rays.

The Florida Marlins became theMiami Marlins.

With interleague play expanded to occur throughout the season, the Houston Astros transferred to the AL West to accommodate each league with 15 clubs apiece.

The Los Angeles Angels of Anaheim became theLos Angeles Angels.

The Cleveland Indians became theCleveland Guardians.

The Oakland Athletics temporarily moved toWest Sacramento, California, and branded themselves as simply the "Athletics" and "A's" with no city name attached, until they permanentlyrelocate to Las Vegas in 2028 or later when theirnew ballpark is completed.^[6]

• List of defunct and relocated Major League Baseball teams
• Expansion of Major League Baseball
• Timeline of Negro league baseball teams

• History of Major League Baseball
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• Major League Baseball lists by team

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