How the league shrank to six

The NHL was founded in 1917 with four Canadian teams. By the late 1920s the league had expanded to 10 teams, including the New York Americans, Pittsburgh Pirates, Philadelphia Quakers, Ottawa Senators (original), and Montreal Maroons. The Great Depression killed franchises one by one — Pittsburgh folded after 1929-30, Ottawa relocated to St. Louis (Eagles) and folded after 1934-35, Philadelphia folded after 1930-31, the Maroons folded after 1937-38.

The New York Americans were the last casualty — they suspended operations after 1941-42 and never returned. From the 1942-43 season through 1966-67, the NHL had exactly six teams: Montreal, Toronto, Detroit, Chicago, Boston, New York. They played 14-game schedules against each other, then expanded to longer schedules in the 1950s and 1960s as travel and television made longer seasons economically viable.

What the Original Six era looked like

Each team played the others 14 times in a typical 70-game season — meaning a player faced the same five opponents over and over for 25 consecutive years. Rivalries became extreme; the Canadiens-Maple Leafs Saturday-night-on-CBC and Sunday-night-on-NBC games of the 1950s and 1960s became Canadian/American religious experiences.

The era was dominated by the Canadiens — 10 Stanley Cup championships in the 25 Original Six years (including 5 in a row from 1956 to 1960, the longest streak in the four major North American sports). Toronto won 9 (the second-most). Detroit won 4. Chicago won 1 (1961). Boston and New York combined for zero in the era. The Maple Leafs’ last Stanley Cup, in 1967, was the final game of the Original Six era — they lost the next year’s playoffs and have not won since (a 57-year drought as of 2024).

1967 expansion and what came after

The 1967 NHL expansion doubled the league to 12 teams: added the LA Kings, California Seals, Minnesota North Stars, Pittsburgh Penguins, Philadelphia Flyers, and St. Louis Blues. All six new teams were placed in a separate Western Division — the league specifically wanted at least one Original Six team in the Stanley Cup Finals each year. The St. Louis Blues lost three consecutive Cup Finals 1968-70 (to Montreal, Montreal, Boston) playing as the Western Division champion.

The ‘Original Six’ name has stuck for marketing purposes. All six franchises still exist with the same names and the same primary cities (Toronto, Montreal, Detroit, Chicago, Boston, New York). They are the only NHL franchises older than 1967. Combined Stanley Cup totals through 2024: Canadiens 24 (the most in any of the four major sports), Maple Leafs 13, Red Wings 11, Bruins 6, Blackhawks 6, Rangers 4.

Background facts cross-referenced with the Wikipedia article on Original Six and Pro-Football-Reference / Basketball-Reference public records.