The Growth of the NHL
Of the four franchises that comprised the National Hockey League (NHL) at the start of the 1917-18 season, only two remain—the Montreal Canadiens and the Toronto Maple Leafs (originally the Toronto Arenas). From 1919-26, eight new teams joined the league, but only four—the Boston Bruins, Chicago Blackhawks (originally Black Hawks), Detroit Red Wings (originally Cougars) and New York Rangers—survived.
It was 41 years before the NHL expanded again, doubling in size for the 1967-68 season with new teams in Bloomington (Minn.), Los Angeles, Oakland, Philadelphia, Pittsburgh and St. Louis. The league had 16 clubs by the start of the 1972-73 season, but it also had a rival in the World Hockey Association, which debuted that year with 12 teams.
The NHL added two more teams in 1974 and merged the struggling Cleveland Barons (originally the Oakland Seals) and Minnesota North Stars in 1978, before absorbing four WHA clubs—the Edmonton Oilers, Hartford Whalers, Quebec Nordiques and Winnipeg Jets—in time for the 1979-80 season. Seven expansion teams joined the league in the 1990s, with two more being added in 2000 to make it an even 30.