The NHL expanded from six teams to twelve teams in 1967 by adding the following teams, which all began play at the start of the 1967-68 season:
Philadelphia Flyers
Pittsburgh Penguins
St. Louis Blues
Minnesota North Stars (moved to Dallas and became the Dallas Stars prior to the 1993-94 season)
Los Angeles Kings
California Seals (moved to Cleveland and became the Cleveland Barons prior to the 1976-77 season; merged with the Minnesota North Stars prior to the 1978-79 season)