From 1942 to 1967, the NHL consisted of exactly six teams — the stretch now nostalgically remembered as the Original Six era. For a quarter-century, the league didn't grow, didn't shrink, and didn't change its footprint. Then, in the summer of 1967, it doubled overnight.
The NHL added six new franchises all at once: the Los Angeles Kings, Minnesota North Stars, Philadelphia Flyers, Pittsburgh Penguins, St. Louis Blues, and the California (originally Oakland) Seals. Twelve teams took the ice for the 1967-68 season where six had played the year before — the single largest one-time expansion in the league's history.
The push to expand wasn't just about growing the sport for its own sake. A U.S. television deal was part of the motivation, since networks wanted access to major media markets beyond the small handful of American cities the Original Six already covered. There was also real concern about a rival professional league forming to claim untapped markets in the western and southern United States — expanding preemptively meant the NHL controlled that territory itself.
The early expansion teams had a rough go of it competitively. To soften the transition, the league split into two divisions for several years — one made up entirely of the six new expansion teams, the other made up of the six established Original Six clubs. That structure guaranteed an expansion team would reach the Stanley Cup Final in the league's early expansion seasons, even though none of them were remotely a match for the veteran Original Six rosters once they got there.
What 1967 really set in motion wasn't just twelve teams — it was the template for every expansion that followed. The NHL has continued adding franchises in waves ever since, growing to the 32-team league recognized today. All of it traces back to that one summer when the league decided six was no longer enough.