History of organizational changes in the NHL

Since being founded in 1917, the National Hockey League (NHL), which in its first two seasons started out as a three-team league and eventually grew to 31 in its current state, has expanded and contracted numerous times throughout its history. The following is a complete history of organizational changes in the NHL.

Three teams (1917–19)
The four teams that began the inaugural NHL season were the Montreal Canadiens, the Montreal Wanderers, the Ottawa Senators, and Toronto. However, after completing four games out of the scheduled 22, the Wanderers withdrew from the league due to their arena burning down, and the NHL continued this season and the next with only three teams.

Four teams (1919–24)
In its third season, 1919–20, the NHL underwent its first expansion, adding the Quebec Bulldogs. Toronto changed its name to Toronto St. Patricks. The next season, however, Quebec relocated to Hamilton, becoming the Hamilton Tigers. These same four teams continued playing for four seasons, up to 1923–24.

Six teams (1924–25)
Two new teams joined the NHL in its eighth season, the Boston Bruins and the Montreal Maroons.

Seven teams (1925–26)
The next season, the NHL added another new team, the Pittsburgh Pirates, and relocated the Hamilton Tigers to New York as the New York Americans.

Ten teams (1926–31)
The NHL continued to expand the following season, adding the Chicago Black Hawks, the Detroit Cougars, and the New York Rangers, growing to ten teams, thus more than doubling its size in its first decade of existence. During the 1926–27 season, Toronto was renamed the Toronto Maple Leafs, taking effect next season. For the 1930–31 season, the Pirates moved from Pittsburgh to Philadelphia, becoming the Philadelphia Quakers, and Detroit was renamed the Detroit Falcons.

Eight teams (1931–32)
After fourteen seasons of steady expansion, the NHL contracted to eight teams, dropping the Philadelphia Quakers and the Ottawa Senators for the 1931–32 season.

Nine teams (1932–35)
For the 1932–33 season, after missing one season, the Ottawa Senators rejoined the NHL, and the Detroit Falcons were renamed the Detroit Red Wings. Two seasons later, for the 1934–35 season, the Ottawa Senators relocated, becoming the St. Louis Eagles.

Eight teams (1935–38)
The Eagles folded after one season, and the NHL was once again an eight-team league for three seasons.

Seven teams (1938–42)
The Montreal Maroons withdrew from the league for the 1938–39 season, further reducing the number of teams in the NHL to seven, shrinking to the size the league was in 1925–26. Play continued for four seasons with seven teams, with the New York Americans changing their name to the Brooklyn Americans for the 1941–42 season, their last.

Six teams (1942–67)
The 1942–43 season saw the folding of the Brooklyn Americans, thus ushering in the Original Six era of the NHL, which lasted without any organizational changes for twenty-five seasons until the 1967 expansion, which doubled the number of teams in the league.

Twelve teams (1967–70)
For the 1967–68 season, six new teams were added to the NHL: the California Seals, the Los Angeles Kings, the Minnesota North Stars, the Philadelphia Flyers, the Pittsburgh Penguins, and the St. Louis Blues. During their first season, the California Seals were renamed the Oakland Seals.

Fourteen teams (1970–72)
The Oakland Seals were renamed the California Golden Seals for their fourth season in 1970–71. The same season the NHL added two new teams, the Buffalo Sabres and the Vancouver Canucks.

Sixteen teams (1972–74)
Two more teams joined the NHL two seasons later, the New York Islanders and the Atlanta Flames.

Eighteen teams (1974–78)
Once again after two seasons, two more teams started play in the NHL, the Washington Capitals and the Kansas City Scouts. Two seasons later, however, the California Golden Seals relocated and became the Cleveland Barons, and the Kansas City Scouts moved as well, becoming the Colorado Rockies.

Seventeen teams (1978–79)
For the first time since the 1942–43 season the NHL contracted, merging the Cleveland Barons into the Minnesota North Stars.

Twenty-one teams (1979–91)
Four teams joined the NHL the next season, coming over from the defunct rival league, the World Hockey Association (WHA). These were the Edmonton Oilers, the Hartford Whalers, the Quebec Nordiques, and the Winnipeg Jets. This doubled the number of Canadian teams in the league. The following season, Atlanta relocated and became the Calgary Flames. In turn, for the 1982–83 season, the Colorado Rockies moved, becoming the New Jersey Devils. Chicago changed their name from the Black Hawks to the Blackhawks for the 1985–86 season. Despite these relatively minor organizational changes, this was one of the more stable periods of NHL history, lasting twelve seasons.

Twenty-two teams (1991–92)
The 1991–92 season saw the dawn of rapid expansion and relocation in the NHL, which lasted for the next ten years, bringing the total number of teams to the current thirty, with the addition of the San Jose Sharks.

Twenty-four teams (1992–93)
Two new teams joined the league the following season, the Ottawa Senators and the Tampa Bay Lightning.

Twenty-six teams (1993–98)
The next season, another two teams were added, the Florida Panthers and the Mighty Ducks of Anaheim. The Minnesota North Stars relocated, becoming the Dallas Stars. Two seasons later, for the 1995–96 season, the Quebec Nordiques relocated and became the Colorado Avalanche. The following season, the Winnipeg Jets also moved, becoming the Phoenix Coyotes. The season after that, the Hartford Whalers relocated, becoming the Carolina Hurricanes.

Twenty-seven teams (1998–99)
The Nashville Predators joined the league for the 1998–99 season.

Twenty-eight teams (1999–2000)
The following season, another team started play, the Atlanta Thrashers.

Thirty teams (2000–2017)
For the NHL's 84th season, thirty teams comprised the league with the addition of the Columbus Blue Jackets and the Minnesota Wild. No new team would join the league for 17 years, making this the longest period of NHL membership stability, as defined by number of franchises, outside of the Original Six era. During this time, one team relocated, two other teams changed their names, and the league dramatically realigned its divisions.

2006: Anaheim name change
The Mighty Ducks of Anaheim changed their name to the Anaheim Ducks for the 2006–07 season, and went on to win the Stanley Cup that season.

2011: Atlanta Thrashers relocation to Winnipeg
After the 2010–11 season, the Atlanta Thrashers relocated to become the current Winnipeg Jets. The team remained in the Southeast Division.

2013 realignment
The league, working in cooperation with the NHL Players Association, dramatically realigned its divisions starting with the 2013–14 season. The realignment saw the two conferences divided on time zone grounds, with the Eastern Conference now featuring all teams located in the and the Western Conference housing all other teams. As part of this realignment, the Columbus Blue Jackets and Detroit Red Wings moved to the East and the Winnipeg Jets to the West.

Each conference went from three divisions to two, with both Eastern divisions having eight teams and both Western divisions having seven. In the East, the "Atlantic Division" name was retained, with the Metropolitan Division being created. In the West, the Central and Pacific Divisions were retained and the Northwest Division was dissolved.

2014: Coyotes name change
After the 2013–14 season, the Phoenix Coyotes changed their geographic identifier (though not their physical location), becoming the Arizona Coyotes.

Thirty-one teams (2017–2021)
In June 2016, the NHL Board of Governors voted unanimously to add an expansion franchise in Las Vegas for the 2017–18 season, with an expansion fee of US$500 million charged. The new team, the Vegas Golden Knights, was placed in the Pacific Division.

Potential COVID-19 changes for 2020–21
With having delayed the conclusion of the 2019–20 season and also being expected to delay and shorten the 2020–21 season, the league is widely expected to adopt a temporary divisional alignment for 2020–21. Because of severe restrictions on cross-border traffic between Canada and the U.S., it is now virtually certain that the Canadian Division, last used in the 1937–38 season, will be revived, and that unlike the previous incarnation, that it will include only Canadian teams. It is expected that the Canadian teams will play only within their division, meaning that no team will have to cross the border during the regular season. No decision has yet been made regarding the season structure for U.S.-based teams.

Thirty-two teams (2021–future)
In December 2018, the NHL granted its 32nd franchise to Seattle, with the fee being US$650 million. The new franchise, eventually unveiled as the Seattle Kraken, will start play in 2021–22. Assuming the league returns to its pre-COVID-19 alignment, the Kraken will play in the Pacific Division, with the Arizona Coyotes moving to the Central Division.

Possible expansion
Despite recent statements from the NHL that no further expansion or even relocation is planned for the foreseeable future, there have been rumors and talks of potential new sites for existing or new teams in various locations in the United States, Canada, and even Europe.