The NHL’s “great expansion” of 1967 delivered hockey to California, led to the “Broad Street Bullies” and legitimized the league as a major force in North American professional sports.

Fifty years ago this week, the owners of the original six teams unanimously approved doubling in size by awarding franchises to Los Angeles, San Francisco/Oakland, Philadelphia, Pittsburgh, St. Louis and Minneapolis/St. Paul. No other pro sports league had ever doubled the number of its teams and the move was considered a gamble.

It proved to be one of the most important decisions in hockey history, and helped convince many that the NHL was for real.

“It had a major impact on the league because thereafter there was almost a lineup for other cities to want to join the league,” said Brian O’Neill, the league’s former director of administration who oversaw the 1967 expansion draft and scheduling. “That was a key to the expansion, to spread the game from California to New York. ... It convinced a lot of people that hockey was a major sport now and it was coast-to-coast and that selling franchises would not be difficult.”

From 1943 to 1967, the NHL was a stable, six-team league made up of the New York Rangers, Boston Bruins, Chicago Blackhawks, Detroit Red Wings, Montreal Canadiens and Toronto Maple Leafs. The move to expand came in the league’s 50th season amid plenty of internal debate.

Owners considered adding two teams at a time, but at their Feb. 7-9 meeting in New York they unanimously approved what President Clarence Campbell later referred to as the “great expansion.” Hockey had some catching up to do: Major League Baseball had 20 teams, the National Basketball Association had nine and the National Football League had 14, with more on the way.

The MLB, the NBA and NFL all had a presence in California, too, something the NHL needed.

“The big issue, of course, is television,” O’Neill said Tuesday.