Six new teams joined the NHL during its major 1967 expansion.
The expansion doubled the league from six teams to twelve. The new clubs were the California Seals, Los Angeles Kings, Minnesota North Stars, Philadelphia Flyers, Pittsburgh Penguins, and St. Louis Blues. The NHL placed all six in a new division, while the established teams formed the other division.
The expansion was partly a response to the growing popularity of hockey in the United States and the challenge posed by the Western Hockey League. It also created a national television opportunity and gave the NHL a much broader geographic footprint.
The six expansion clubs did not immediately compete against the Original Six in a single balanced structure. The division arrangement allowed the new teams to reach the playoffs while the league adjusted. Philadelphia, one of the six, became the first expansion team to win the Stanley Cup, in 1974.