During this early period, players such as forward Howie Morenz of the Montréal Canadiens, defenseman Eddie Shore of the Boston Bruins, and forward King Clancy of the Toronto Maple Leafs drew crowds as the NHL’s first great stars. Several organizers were instrumental in building the NHL in its early days. The most prominent included Frank Calder, the first NHL president; Conn Smythe, who helped build and guide Toronto's franchise; and Jack Adams, a coach and general manager in Detroit from 1927 through 1962.

World War II (1939-1945) drained the league of players, and by 1942 the NHL consisted of only six teams—the Bruins, the Detroit Red Wings, the Chicago Blackhawks, the Canadiens, the New York Rangers, and the Maple Leafs. After the war the six-team NHL era saw the rise of several dynasties. Forward Gordie Howe and goaltender Terry Sawchuk were stars on the Red Wings, who won four Stanley Cup championships between 1950 and 1955. The Canadiens, spearheaded by forward Maurice Richard, played in the Stanley Cup Finals each year from 1951 through 1960, winning in 1953 and from 1956 to 1960.

Hockey gained popularity in the 1960s, and late in the decade the NHL began to expand. The league added ten teams from 1967 to 1972. Hockey’s strength as a spectator sport was also shown by the creation in 1971 of the World Hockey Association (WHA), a rival professional league to the NHL. In the summer of 1972 the sport’s popularity received another boost with an eight-game competition between Canada’s best professionals and the top players from the USSR’s Red Army team. The heavily favored Canadians, stunned by the Soviets' prowess, barely edged the Red Army team, 4 games to 3 (with 1 tie). The series came down to the last game, which the Canadians won on a last-minute goal scored by Paul Henderson, who remains a national hero. A fierce rivalry was born, and a subsequent series took place in 1974.

The merger of the WHA and the NHL in 1979 and the entry of 18-year-old center Wayne Gretzky into professional play the same year marked the beginning of unprecedented popularity for ice hockey. Gretzky, who came to be called “The Great One,” dominated the league over the next 15 years with a streak of unprecedented scoring accomplishments. Other powerful scorers such as centers Mario Lemieux and Mark Messier, left wing Brett Hull, and defenseman Paul Coffey were regarded as the best hockey players of the late 1980s and early 1990s.

The 1980 Winter Olympics in Lake Placid, New York, also helped spark the boom in ice hockey, at least in the United States. During the Games the U.S. Olympic men’s hockey team, a collection of college and minor-league players, defeated the powerful USSR en route to the gold medal. The victory sparked the formation of several new minor leagues and teams in the United States, plus expansion by the NHL into new American markets.