On May 15, 1967, Chicago traded forwards Phil Esposito, Ken Hodge, and Fred Stanfield to the Boston Bruins for defenseman Gilles Marotte, center Pit Martin, and goalie Jack Norris.
This was a disastrous trade by the Blackhawks. Had they not made this trade, they could have won a couple of Stanley Cups in the 70's. This trade alone was a franchise turner for the Bruins, who were among the best teams in the 1970's.
That trade also allowed the Bruins to make one of their biggest trades in team history: On Nov. 7, 1975, Boston traded center Phil Esposito and defenseman Carol Vadnais to the Rangers for defenseman Brad Park, center Jean Ratelle and defenseman Joe Zanussi in what would become one of the most monumental trades of the decade. The trade was a very good one for the Bruins since Esposito was on his last legs. Ratelle was also near the end of a very productive career, but Brad Park was still an all-star calibre defenceman at the time. The Bruins remained competitive and would have won another Cup or two had it not been for the Montreal Canadiens. The Rangers made it to the Cup final the year they obtained Esposito. But it's quite possible that they would have made it there even if they hadn't made the trade. Goalie John Davidson was spectacular that season and led them to the final.