The NHL grew to six teams in 1924, adding a second team in Montreal, the Maroons, and the first American team, the Boston Bruins. The Bruins were purchased by Charles Adams, a grocery store financier who first developed an interest in hockey during the Stanley Cup playoffs, paying $16,000 for the team. The Maroons were created to replace the Wanderers and to appeal to the English population of Montreal. The first NHL game played in the United States was a 2–1 Bruins victory over the Maroons at the Boston Arena on December 1, 1924.
The Montreal Forum, which in later decades became synonymous with the Canadiens, was built in 1924 to house the Maroons. The Canadiens did not move into the Forum until two years later. The Forum hosted its first Stanley Cup final in its second year, as the Maroons defeated the WCHL's Victoria Cougars in the 1926 Stanley Cup Finals, the last time a non-NHL team competed for the Cup.
The New York Americans began play in 1925 along with the NHL's third American-based team, the Pittsburgh Pirates. Three more teams were added for the 1926–27 season. Tex Rickard, operator of Madison Square Garden, had reluctantly allowed the Americans into his arena the year before. However, the Americans were so popular in New York that Rickard felt his arena could support a second team. As a result, the New York Rangers were granted to Rickard on May 15, 1926. In November of that year, the league announced that the cities of Detroit, Michigan and Chicago, Illinois would get teams. Detroit purchased the assets of the Victoria Cougars to stock the expansion Detroit Cougars. The players of the Portland Rosebuds were sold to coffee tycoon Frederic McLaughlin for his new Chicago Black Hawks team. The three new franchises brought the NHL to ten teams.
The Rangers reached the 1928 Stanley Cup Finals, in just their second season, against the Maroons. Lorne Chabot was injured early in the second game of the series, leaving the Rangers without a goaltender. As the Maroons were unwilling to allow the Rangers to substitute a goaltender watching from the Montreal Forum stands, Rangers coach Lester Patrick was forced into goal himself. A defenceman during his playing days, the 44-year-old Patrick allowed only one goal on 19 shots as the Rangers won the game in overtime, 2–1. The Rangers signed New York Americans goaltender Joe Miller the next day, and went on to capture the Stanley Cup in five games.