This was done in order to keep teams of similar competitive strength in the same division, regardless of geographic distance,[1] and to ensure playoff revenue for the new franchises.
Another consequence was that in 1969–70, the Montreal Canadiens, who had finished the season with 92 points (more than any team in the West Division), missed the playoffs – the only time between 1948–49 and 1993–94 that they did so.
By 1974, another two teams (the Washington Capitals and Kansas City Scouts) entered the NHL, and as a result the league underwent a major overhaul.
The East and West Divisions were renamed the Prince of Wales and Clarence Campbell Conferences, respectively, composed of nine teams each.
The East and West Divisions were re-formed for the 2020–21 season as the result of the COVID-19 pandemic which forced the NHL to radically re-structure the league and to temporarily abolish the conferences.