Expansion of Major League Baseball

Major League Baseball (MLB), the highest level of professional baseball in the United States and Canada, has undergone several rounds of expansion beginning in, eventually reaching 30 teams with its most recent expansion taking place in. MLB has discussed preparations for another round of expansion. Several investment groups are vying for an MLB franchise.

Background
For a 50-year period from 1903 to 1952, MLB's 16-team structure (split into the American and National Leagues) remained intact. No franchises were relocated during this period, and five markets—Boston, Chicago, New York City, Philadelphia, and St. Louis—had two or more teams. According to authors Andy McCue and Eric Thompson, "The less financially successful clubs in two-team cities were finding it increasingly difficult to compete" by the early 1950s. In addition, population changes in the United States were leading to many citizens moving away from the Northeast, where many MLB teams were based, to southern and western locations.

From 1953 to 1955, three franchises were relocated, all of which had been in markets with two or more teams. Prior to the 1958 season, the two New York City teams in the NL, the Brooklyn Dodgers and New York Giants, moved westward; the Dodgers relocated to Los Angeles, while San Francisco became the new home of the Giants.

MLB's perceived threat of proposed Continental League
Due to the relocation of the Dodgers and Giants, a third major league for baseball, the Continental League, was proposed by lawyer William Shea in November 1958. Shortly after in December, MLB had created an Expansion Committee. On July 27, 1959, the new league was formally announced, with teams in Denver, Houston, Minneapolis–St. Paul, New York City, and Toronto, with three other cities later picked by January 1960, Atlanta, Dallas–Fort Worth, and Buffalo, set to start on April 18, 1961. In addition to the pressures of the proposed Continental League, MLB was facing pressure from the U.S. Congress, which indicated that efforts to prevent future expansion would arouse interest in weakening the sport's exemption from antitrust laws. Congress voted on a bill aimed at repealing the exemption, but it failed.

However, MLB moved to expand after a rival league became a possibility. MLB formed an expansion committee, which voted in favor of adding four new teams, two in each league, by 1961–62. MLB sought cities that had received interest from the Continental League as a means to stop its formal start. Among them, were Houston, Los Angeles, New York City, and Washington, D.C, which were all granted franchises by late 1960. As a concession by William A. Shea, part of his negotiations with Major League Baseball to expand to incorporate at least eight new teams, the Continental League formally disbanded on August 2, 1960.

Los Angeles Angels
Actor Gene Autry led a group that paid $2.1 million for the right to place an MLB team in Los Angeles. Autry, who owned radio stations, had been seeking to acquire a contract to broadcast baseball games when he traveled to MLB's Winter Meetings. After the Meetings, on December 6, 1960, his group received franchise rights. The Los Angeles team was initially scheduled to begin play in 1962, but a relocation plan elsewhere in the AL resulted in the start date being moved up to 1961. The club was named the Los Angeles Angels, after a Pacific Coast League team that had previously played in the city. To secure the name rights, Autry paid a $350,000 fee to Dodgers owner Walter O'Malley, who had purchased the minor league Angels before relocating the Dodgers to Los Angeles.

Washington Senators
While initially, leading figures in Minneapolis–St. Paul, Minnesota, had sought an expansion franchise, in October 1960, the AL permitted the Washington Senators to move in time for next year's season, and gave Washington, D.C., an expansion team. The former Senators changed their name to the Minnesota Twins, and the new expansion team took the Senators name. The decision was partially in response to pressure from Congress, which had wanted a replacement for the former Senators. As with the Angels' ownership group, the new Senators' owners paid a $2.1 million fee for the right to an MLB franchise. This new Washington Senators group plays today in the Dallas–Fort Worth metroplex following relocation in 1972 as the Texas Rangers.

1962 NL expansion: Houston Colt .45s and New York Mets
The NL announced an expansion as the 1960 World Series was in progress, with new teams in Houston and New York City. William Shea had been a supporter of the Continental League concept, and had attracted several investors. A potential Houston team also had numerous partners, many of whom had oil interests. The AL initially showed interest in adding a Houston team, but the investors wanted an NL franchise. MLB granted the two cities franchises on October 17, 1960.

Houston Colt .45s
The Houston Sports Association was formed in 1957 and bought a minor league baseball team four years later. The group was given a controlling interest in Houston's expansion team, which was named the Houston Colt .45s. It played at Colt Stadium. It would only be a few years later in that the team would become the Houston Astros. In, the Astros transferred into the American League.

New York Mets
Following the announcement of the Dodgers and Giants leaving New York City, the city formed the Mayor's Committee, headed by lawyer William Shea. Though New York City sought a replacement NL franchise (strongly supported by city Mayor Robert Wagner), MLB displayed little intention of adding a New York team, despite the formation of the Expansion Committee. With Shea's Continental League project and pressure from Congress, MLB eventually gave in and rewarded New York with a National League franchise, effectively killing the Continental League project. On May 8, 1961, the club announced the name of the team would be the New York Mets, named after a shortened version of the 1880s team, the New York Metropolitans.

The city was unable to secure funding for a proposed Flushing Meadows stadium in time for play in 1962, so the Mets played at the Polo Grounds, the previous home of the New York Giants. George Weiss was the president of the team, and seven-time World Series championship-winning manager Casey Stengel was hired to lead the Mets on the field. Thanks to Shea's efforts to bring National League baseball back to New York, Shea Stadium the stadium the Mets would play in from 1964 to 2008, was named in his honor.

Kansas City Royals
Following the departure of the Kansas City Athletics to Oakland following the end of the, US Senator Stuart Symington threatened to challenge Major League Baseball's antitrust exemption with federal legislation, and to also challenge the reserve clause. Kansas City mayor Ilus Davis threatened a lawsuit to block the move. Tom Yawkey arranged a meeting of the owners during a convention, during which the league agreed to accelerate the expansion process and assured that Kansas City would be granted a new franchise to begin play no later than the. This would require another franchise to be established at the same time to ensure the league had an even number of teams for a balanced schedule. Ewing Kauffman won rights to the franchise and paid a $5.5 million expansion fee for the Kansas City Royals, which played games at Municipal Stadium until the end of the 1972 season, after which the team moved to Royals Stadium, now known as Kauffman Stadium.

Seattle Pilots
Because of failed attempts to attract existing teams, Seattle instead tried to lobby for an expansion franchise at the 1967 owners' meetings in Chicago. The delegation also had support from two US Senators, Henry M. Jackson and Warren Magnuson, the latter of whom was the chairman of the Senate Commerce Committee, a committee which has "jurisdiction over the major league's business activities". Coupled with Symington's threats related to the move of the Kansas City Athletics, the political influence swayed the American League owners. However, they were reluctant to expand in 1969 without a Seattle stadium bond issue. The Seattle delegation assured the owners that Sick's Stadium could be renovated in five months to fulfill the minimum requirements until a new stadium was built; with this, the owners agreed to a 1969 expansion, and approved teams in Kansas City and Seattle.

In December 1967 at the Winter Meetings in Mexico City, the franchise was officially awarded to Pacific Northwest Sports, led by Dewey Soriano, which received $5.5 million in funding from William R. Daley, who thus had 47% ownership of the venture. Other owners included Max and Dewey Soriano. The award was contingent on renovation of Sick's Stadium to increase its seating capacity from 11,000 to 30,000 by the start of the 1969 season. The Sorianos persuaded notable athletes to advocate for the $40 million King County stadium bond issue, including baseball players Mickey Mantle, Carl Yastrzemski, and Joe DiMaggio, and football player Y. A. Tittle; the bond issue was approved by 62.3% of the electorate. The Seattle Pilots would eventually be declared bankrupt in 1970 and the team was sold to Bud Selig, who moved the team to Milwaukee after only one season in Seattle and renamed it as the present-day Milwaukee Brewers. The team would eventually be transferred to the National League in as a result of expansion that season.

Montreal Expos
Montreal City Councilor Gerry Snyder spoke to Ford Frick sometime after the 1962 Major League Baseball expansion, during which he was told Montreal would not receive an expansion franchise unless it had a stadium in which to contest matches. At the Winter Meetings in Mexico City on December 2, 1967, Snyder presented a proposal to Major League Baseball owners to establish a franchise in the city. Several influential owners pledged their support for a Montreal franchise in that meeting, including Walter O'Malley, Roy Hofheinz, and John Galbreath. Certain that Hofheinz would object to a Dallas–Fort Worth bid and that the San Diego bid was near certain to be successful, Snyder deemed a bid from Buffalo to be the strongest bid against which to compete.

On 27 May 1968, the National League officially awarded a franchise to Montreal to commence play in the 1969 season. National League president Warren Giles had encouraged the owners during the meeting, stating "If we're going to expand, let's really spread it out". The Montreal Expos became the first franchise to be awarded to a city outside the United States. When the news reached the U.S. Congress, members collectively condemned the decision.

Because of the slow pace of progress in meeting commitments, Jean-Louis Lévesque withdrew his financial support in the franchise on July 31, 1968. Snyder quickly found another investor, Charles Bronfman, and the team met the deadline of 15 August for the initial $1.1 million installment, before which Jarry Park was selected as the team's stadium for the short term. Renovations to the park were made by adding uncovered bleacher seats along the right and left field lines, and an electronic scoreboard installed beyond right field. The team had some issues committing to a new stadium, as required by the franchise award, and it was said that the team had agreed to build a dome at the Autostade and use it as their stadium if a new stadium was not built by 1970. It had originally intended to lease the stadium and expand its seating capacity from 26,000 to 37,000, but then chose Jarry Park instead.

The ownership group paid $12.5 million for the team. John McHale was hired as the team's first president, and Jim Fanning its first general manager. Many names had been considered for the team, including Royals which had a strong association with the city, but the name had already been adopted by the new Kansas City franchise. After rejecting various options, including "Voyageurs" and "Nationals", the name Expos was chosen in honour of Expo 67 and because it was the same in both of the city's official languages. McHale stated that the name would "help Montreal be identified properly as the city that gave the world Expo 67".

The Montreal Expos would eventually relocate to Washington, D.C. for the as the Washington Nationals.

San Diego Padres
In 1967, C. Arnholt Smith, owner of the PCL San Diego Padres (PCL), won a bid for an expansion team in the National League for the. On May 27, 1968, the National League officially awarded a franchise to San Diego to commence play in the 1969 season for a fee of $12.5 million for the team. After the 1968 PCL season, Smith surrendered the franchise, which moved to Eugene, Oregon, and transferred the Padre name to his new NL team, the San Diego Padres. Eddie Leishman was named general manager of the MLB Padres, with club president and minority investor Buzzie Bavasi, formerly GM of the Los Angeles Dodgers (having resigned to take the new role), playing a dominant role in its baseball operations as president of the team.

Seattle Mariners
Following the bankruptcy and departure of the Seattle Pilots on April 1, 1970, the city of Seattle, King County and the state of Washington sued the American League for breach of contract. The $32.5 million lawsuit proceeded until 1976, when at trial the American League offered the city a franchise in exchange for the city, county, and state to drop the suit. On November 2, 1972, King County had broken ground on the Kingdome, which would come to be used by the Seattle Mariners for baseball and by the Seahawks for football.

On January 15, 1976, the expansion franchise was approved, becoming the 13th franchise in the American League. It was owned by Lester Smith and Danny Kaye, who paid an expansion fee of US$6.5 million. Owing to the history surrounding the franchise, sportswriter Emmett Watson of the Seattle Post-Intelligencer joked that the team should be named the Seattle Litigants.

Toronto Blue Jays
Toronto had previously been involved with the failed Continental League. In 1974, the Toronto City Council approved a further CA$2.8 million for renovations to Exhibition Stadium, retrofitting the stadium for baseball and would be ready in time for the 1977 season. There had been strong interest from several groups and individuals to own a Major League Baseball team in the city. The most prominent was Labatt Brewing Company, who wanted to use ownership of a sports team as a means to establish a visible presence in the Toronto market. Labatt Brewing Company would go on to fail at acquiring and relocating the Baltimore Orioles and the Cleveland Indians to Toronto. Soon after in February 1976, the Labatt Brewing Company would again fail to acquire and relocate a third team, this time the San Francisco Giants. Following this failure, Toronto City Council alderman Paul Godfrey received a phone call from Kansas City Royals owner Ewing Kauffman informing him that he supported a Toronto franchise for the American League.

During an owners meeting held on March 20, 1976, the American League franchises voted 11-1 to expand the league with a Toronto franchise, to which National League owners resolved to consider a Toronto franchise to begin play in the 1977 season. Bowie Kuhn, at the time the Commissioner of Baseball, planned for the National League to expand with new franchises in Toronto and Washington, D.C., and for the American League to add a new franchise in New Orleans in addition to the already-awarded Seattle franchise. On March 29, National League owners met and voted in favour of the expansion plans, but they were rejected because the vote was not unanimous, with dissenting votes from the owners of the Cincinnati Reds and Philadelphia Phillies. A subsequent vote on April 26 ended this plan with a 7–5 result in favour of the proposal, again failing to achieve unanimity.

Two groups bid for the rights to franchise ownership in the city, which presented bids during an American League owner's meeting on March 26, 1976. Ultimately, an ownership group named Metro Baseball Ltd. consisting of Labatt Brewing Company, the Canadian Imperial Bank of Commerce, and Imperial Trust won the bid for a franchise fee of CA$7 million. The other bid was made by Atlantic Packaging. The winning bid was represented by legal counsel Herb Solway and Gord Kirke. Kirke prepared the original documents which led to the foundation of the team in 1976, named the Toronto Blue Jays.

1993 NL expansion: Colorado Rockies and Florida Marlins
In June 1991, the MLB expansion committee accepted the bids of the Miami and Denver groups to debut in 1993. Expansion was approved unanimously by all teams in July 1991.

Colorado Rockies
Denver, Colorado had previously been involved with the failed Continental League. After previous failed attempts to bring Major League Baseball to the state of Colorado (most notably the Pittsburgh Pirates nearly relocating to Denver following the Pittsburgh drug trials in 1985), by the late 1980s a team seemed to be a possibility in Denver. Eugene Orza, associate general counsel of the Major League Baseball Players Association, stated that he expected Denver would receive one of the expansion franchises.

The Colorado Baseball Commission, led by banking executive Larry Varnell, was successful in getting Denver voters to approve a 0.1% sales tax to help finance a new baseball stadium. Also, an advisory committee was formed in 1990 by then-Governor of Colorado Roy Romer to recruit an ownership group. The group selected was led by John Antonucci, an Ohio beverage distributor, and Michael I. Monus, the head of the Phar-Mor drugstore chain. Local and regional companies—such as Erie Lake, Hensel Phelps Construction, KOA Radio, and the Rocky Mountain News—rounded out the group. The Denver group chose to call their franchise the Colorado Rockies, the same name used as the National Hockey League franchise that played in Denver from 1976 to 1982.

Florida Marlins
U.S. Senator Connie Mack III from Florida, the grandson of baseball great Connie Mack and a member of the Senate Task Force on Major League Baseball, pushed Baseball Commissioner Fay Vincent to expand to Florida.

On June 10, 1990, Wayne Huizenga, CEO of Blockbuster Entertainment Corporation, was awarded an expansion franchise in the National League (NL) for a $95 million expansion fee and the team began operations in 1993 as the Florida Marlins, beating out bids in Orlando and Tampa Bay. Orlando fielded a very spirited campaign bolstered by its family-oriented tourism industry. Tampa Bay already had a baseball park — the Florida Suncoast Dome in St. Petersburg, completed in 1990. The Miami group chose to call themselves the "Florida" Marlins to broaden their fanbase to the entire state, while reviving the nickname "Marlins" from previous minor league teams, the Miami Marlins of the International League from 1956 to 1960, and the Miami Marlins (1962–1970) and Miami Marlins (1982–1988) teams that played in the Florida State League.

With the enfranchisement of a team in the Tampa Bay area and a new stadium in Miami proper, the Florida Marlins would rename as the Miami Marlins in 2012.

Arizona Diamondbacks
In the fall of 1993, Jerry Colangelo, majority owner of the Phoenix Suns, the area's NBA franchise, announced he was assembling an ownership group, "Arizona Baseball, Inc.", to apply for a Major League Baseball expansion team. This was a local group formed to preserve Cactus League spring training in Arizona and eventually secure a Major League franchise for the state.

Colangelo's group was so certain that they would be awarded a franchise that they held a name-the-team contest for it, with the final choice being "Diamondbacks", after the Western diamondback, a rattlesnake native to the region known for injecting a large amount of venom when it strikes.

Colangelo's bid received strong support from one of his friends, Chicago White Sox and Chicago Bulls owner Jerry Reinsdorf, and media reports say that then-acting Commissioner of Baseball and Milwaukee Brewers founder Bud Selig was also a strong supporter of Colangelo's bid. Plans were also made for a new retractable-roof ballpark, to be built in an industrial/warehouse district on the southeast edge of downtown Phoenix, one block from the Suns' America West Arena (now Footprint Center). On March 9, 1995, Colangelo's group was awarded a franchise to begin play for the. A $130 million franchise fee was paid to Major League Baseball in four payments, over the course of three years. In addition, the Diamondbacks gave away their rights to $5 million from baseball's central fund for each of the five years following expansion (1998–2002).

Arizona had originally been intended to join Tampa Bay in the American League. However, five American League teams had threatened to block the league assignments because of concerns that they would have additional games out of their time zone, causing early starts that would decrease revenue and TV ratings. Thus, on January 16, 1997, the Arizona Diamondbacks were officially voted into the National League while their expansion counterparts in Tampa Bay were voted into the American League.

Tampa Bay Devil Rays
After failing to land an expansion team for the 1993 season, the Tampa Bay Baseball Group, the group leading the Tampa Bay area for an expansion team, sued MLB for allegedly reneging on an agreement to grant an expansion team to Tampa.

Like Phoenix, Arizona, on March 9, 1995, Tampa Bay Baseball Group was awarded a franchise to begin play for the 1998 season, and paid an identical $130 million franchise fee that was paid to Major League Baseball in four payments, over the course of three years. Similarly, the Tampa Bay Devil Rays gave away their rights to $5 million from baseball's central fund for each of the five years following expansion (1998–2002).

The suit that was launched in response to the failed 1993 expansion was settled in 2003, five years after the Devil Rays began play in the American League. In 2008, the team would rebrand to their current name, the Tampa Bay Rays.

Expansion drafts
There have been six expansion drafts in MLB history.

Potential future expansion sites
After the 2017 season, Tracy Ringolsby of Baseball America wrote that there was "a building consensus" that MLB would expand to 32 teams. He said that the proposed expansion would allow for divisional realignment to address concerns with travel and off-days in the schedule. Ringolsby also reported that a team would likely go to Portland, Oregon, with Manfred citing a need for another team in the western United States.

After Sportico estimated the average value of an MLB franchise to be $2.2 billion in April 2021, Manfred called it a "lodestar" for negotiations for an expansion fee for the team's new owners. Tony Clark, the president of the MLB Players Association, voiced his support for expanding MLB to 32 teams the following year.

In April 2023, the Athletics entered into an agreement to relocate to Las Vegas. Las Vegas had been seeking an MLB franchise, either through expansion or relocation of an existing team. On September 19, 2023, the Rays announced plans to build a new ballpark in St. Petersburg adjacent to Tropicana Field, as part of the redevelopment of the Gas Plant District, which is planned to open for the 2028 season. It is expected to be a 30,000 seat fixed-roof stadium which will cost $1.3 billion.

In April 2024, the Athletics announced they had entered into an agreement with Sacramento River Cats owner Vivek Ranadive to play the 2025–2027 seasons at their home stadium, Sutter Health Park in West Sacramento, California.

Austin
The Austin Baseball Commission LLC was launched in mid-July 2024, a grassroots organization devoted to bringing a major-league baseball team to Austin, Texas. The organization, founded by marketer Derrik Fox with help from Matt Mackowiak, head of the Travis County Republic Party and founder of Save Austin Now PAC, has the support of Williamson County Judge Bill Gravell and Austin Mayor Kirk Watson. The group cites the early success of the MLS Austin FC team as "proof of concept" that an MLB team could work.

Charlotte
The Charlotte Bats is an organization devoted to bringing a major-league baseball team to Charlotte, North Carolina. In March 2023, the deputy mayor of Charlotte said that no plans for a stadium have been submitted to the Charlotte City Council for consideration.

Montreal
The Montreal Expos, a 1969 expansion team, played for 36 seasons in the NL East before relocating to Washington, D.C., in 2004, becoming the Washington Nationals.

In 2019, the Rays received permission to explore splitting their seasons between Tampa Bay and Montreal. MLB rejected the Rays' plan in January 2022.

In 2015, Denis Coderre, the mayor of Montreal, and Stephen Bronfman, the son of Expos owner Charles Bronfman, wrote a letter to all 30 MLB teams extolling Montreal as an expansion city. Bronfman is leading a group of investors who are looking to obtain an MLB franchise. He announced an agreement to develop land that would house a new stadium on a 40 acre plot of land off of Bonaventure Expressway in Peel Basin. His partners include Pierre Boivin, Alain Bouchard, and Mitch Garber. According to The Canadian Press, the ownership group has met MLB's conditions for returning to Montreal.

Nashville
Music City Baseball was founded in 2019 by John Loar and Alberto Gonzales. They brought on Dave Stewart to lead them publicly. The organization is devoted to the founding of a major league team in Nashville, named the "Nashville Stars", after the Negro league team of that name. The group initially sought land for a stadium by the Cumberland River, but as of June 2022 was focused on North Nashville near Tennessee State University. The group hopes to privately fund the stadium.

Orlando
Orlando, Florida, has expressed interest in a team, despite the state of Florida already being home to two MLB franchises, in Miami and the Tampa Bay area. In November 2019, Pat Williams, a co-founder of the Orlando Magic of the National Basketball Association (NBA), unveiled the "Orlando Dreamers", a concept for an MLB expansion team in Orlando. Thousands of people indicated interest in buying season tickets on the Orlando Dreamers website in the 24 hours after the announcement. The group has proposed building a 45,000-capacity domed stadium on a 35.5 acre lot near the Orange County Convention Center along with 1,000 hotel rooms, estimating a cost of $1.7 billion. As of May 2023, the group was seeking $975 million in public funds.

Portland
The Oregon Legislative Assembly passed Senate Bill 5 in 2003, which could provide $150 million in public funds towards building a stadium.

In 2017, the Portland Diamond Project (PDP) was formed by Craig Cheek, a retired vice president for Nike, Inc., and Mike Barrett, a former broadcaster for the Portland Trail Blazers of the NBA. Russell Wilson and Ciara invested in the group in 2018.

In 2018, PDP announced an agreement with the Port of Portland to build a 32,000-seat stadium along the Willamette River on a 45.5 acre tract of land at Terminal 2 in Northwest Portland. Architecture firm Populous would build the stadium if the proposal is approved. By 2023, PDP had shifted focus and was considering sites at the Lloyd Center shopping mall in downtown Portland or the Redtail Golf Course in neighboring Beaverton. In January 2024, they announced they were in negotiations to purchase the 164 acre Redtail site.

Raleigh
Tom Dundon, the owner of the Carolina Hurricanes of the National Hockey League, has stated his intent to lead a group to submit a bid to bring MLB to Raleigh, North Carolina, during the next phase of expansion. The Hurricanes have committed long-term to the city, until at least 2044, along with the approved $1.1 billion in upgrades for PNC Arena and development of a sports and entertainment district around the arena, which could include a baseball stadium. Dundon has stated that securing the capital necessary is a non-issue.

Sacramento
In April 2024, the Oakland Athletics entered into an agreement to play three or more seasons at the Sacramento River Cats home field, Sutter Health Park in West Sacramento, California. After the press conference announcing the move, Vivek Ranadivé, owner of the River Cats and the Sacramento Kings, stated that, in conversations with MLB Commissioner Rob Manfred, he was told that MLB was seeking to add a west coast expansion franchise. Ranadivé added that he felt Sacramento would move into "pole position" for a new team, with the A's sojourn being a "good showcase" for the Sacramento market. Ranadivé mentioned the Sacramento Railyards, originally intended as the site for a MLS expansion stadium, as the potential site of a new ball park. Later in the day, Sacramento Mayor Darrell Steinberg also made mention of Sacramento's intention to seek an MLB expansion franchise during a press conference from city hall, referring to the A's stint in Sacramento as an "audition" for MLB.

Salt Lake City
In April 2023, Gail Miller, the widow of Utah Jazz owner Larry H. Miller and co-founder of the Larry H. Miller Company, announced the formation of Big League Utah, a group of investors looking to obtain an expansion MLB franchise for Salt Lake City. They also announced their partnership with Rocky Mountain Power to develop a 100 acre lot on the city's west side for a stadium. On February 15, 2024, the Larry H. Miller company announced that they plan to invest at least $3.5 billion to towards the lot, bringing mixed-use development to the area, including a baseball stadium.

Teams
The MLB originated in 1903 with 16 teams, from the signing of the National Agreement between the National League (founded 1876) and the American League (founded 1901). Through a sequence of team expansions, contractions, and relocations, MLB currently consists of 30 teams. The United States is home to 29 teams and one is located in Canada.

The following table shows current MLB teams that are participating in the 2024 MLB season, in which city they are located, when the club was founded, joined the MLB, number of times relocated and times the franchise name has changed.

Current
Notes:

†''Due to the COVID-19 pandemic, the Toronto Blue Jays played the and  seasons across several locations. The team played the 2020 season in Buffalo, New York. In April–May 2021, the team played at their spring training location in Dunedin, Florida, in June–July 2021, the team returned to Buffalo, and returned to Toronto on July 30.''