On January 18, 1958, Willie O'Ree joined the Bruins as an injury call-up for a game in Montreal. In doing so he became the first black player in the NHL. O'Ree played only two games with the Bruins in the 1957–58 season. He returned to the NHL in 1960–61, playing another 43 games with Boston. Although he only played 45 NHL games, scoring four goals, it was enough for him to be labeled the "Jackie Robinson of hockey".
O'Ree faced blatant racism from opponents throughout the season, remarking that "people just wanted a piece of me, maybe because they thought I was different, so I had to defend myself. I wasn't going to be run out of any rink." He faced racial slurs from fans when he played in Chicago, Detroit and New York, though the taunts were mostly absent in Montreal and Toronto. O'Ree was supported by his teammates and the fans in Boston. He stated that "they were mean to me in places like Detroit and New York, too. But never in Boston. I'll never forget how my teammates there—men like Johnny Bucyk, Doug Mohns, Charlie Burns and Don McKenney—took care of me. They accepted me totally. All of them had class." O'Ree was traded to Montreal in 1961 but was unable to crack the Canadiens' line-up. He played over 20 minor league seasons, twice winning the Western Hockey League's scoring title, with the Los Angeles Blades in 1964 and the San Diego Gulls in 1969.
O'Ree's breakthrough came several years after another black player, Herb Carnegie was denied the same opportunity. Playing junior hockey with the Ontario Hockey Association's Toronto Rangers in 1938–39, Carnegie was pulled aside by his coach during a practice: "See that man sitting in the blues? That's Conn Smythe, owner of the Toronto Maple Leafs. He says he'd take you tomorrow if he could turn you white." Stung by the comments, Carnegie resolved to excel at the game. He was offered a tryout with the Rangers in 1950, and a spot on their lowest minor league team. "They told me that if I signed with the Rangers and went to New Haven, I would make international headlines. I told them my family couldn't eat headlines. That was probably when the Rangers decided to forget about me."