A fine player and ambitious promoter, J. Ambrose O'Brien was one of the game's true pioneers. He was actively connected with hockey from its earliest years, rising up through the junior, intermediate and senior ranks in his hometown of Renfrew, Ontario, northwest of Ottawa.
After graduating from the University of Toronto, where he starred on the varsity hockey team, O'Brien became one of hockey's first promoters. After the Eastern Canada Amateur Hockey Association rejected Renfrew's application for a team in 1909, O'Brien almost single-handedly organized the rival National Hockey Association (NHA).
O'Brien was aided by his father, Senator Michael J. O'Brien, who financed four different clubs, even though the family's initial motivation for forming the new loop was to give Renfrew a chance to compete for the Stanley Cup. The most famous team created at this time was the Renfrew Millionaires. Stars such as Lester and Frank Patrick, Cyclone Taylor, and Fred Whitcroft were lured to play giving the league immediate legitimacy.
Apart from Renfrew, the other teams participating were the Montreal Wanderers, Cobalt, Haileybury, Montreal Shamrocks and Ottawa. The Patricks ended up utilizing their substantial salaries to form the rival Pacific Coast Hockey Association in 1911. Within a few days of the decision to form a new league, O'Brien launched the Canadiens, a club composed of French Canadian players which would appeal to a large portion of Montreal.
It was decided the O'Brien Cup, a silver trophy given by JA O'Brien's father, would the championship emblem of the league. This trophy was later adopted by the NHL and presented to the regular season champions before being retired and donated to the Hockey Hall of Fame. O'Brien's efforts during the unstable period around 1910 helped solidify the pro game and lay the groundwork for the formation of the National Hockey League in 1917.
He was elected to the Hockey Hall of Fame in 1962.