The First Openly Gay Ballplayer

Glenn Burke?  Apparently:

This week's coming out by NBA player Jason Collins is momentous, but the Jackie Robinson of gay rights was Glenn Burke, who played for the Los Angeles Dodgers and Oakland A's from 1976 to 1979. He tried to change sports culture three decades ago—but back then, unlike now, sports culture wasn't ready for a change.
Burke made no secret of his sexual orientation to the Dodgers front office, his teammates, or friends in either league. He also talked freely with sportswriters, though all of them ended up shaking their heads and telling him they couldn't write that in their papers. Burke was so open about his sexuality that the Dodgers tried to talk him into participating in a sham marriage. (He wrote in his autobiography that the team offered him $75,000 to go along with the ruse.) He refused. In a bit of irony that would seem farcical if it wasn't so tragic, one of the Dodgers who tried to talk Burke into getting "married," was his manager, Tommy Lasorda, whose son Tom Jr. died from AIDS complications in 1991. To this day, Lasorda Sr. refuses to acknowledge his son's homosexuality.
Burke, who also died of AIDS-related causes in 1995, came out to the world outside baseball in a 1982 article for Inside Sports and even followed it up shortly after with an appearance on The Today Show with Bryant Gumbel. But his story was greeted by the rest of the news media and the baseball establishment, including Burke's former teammates and baseball commissioner Bowie Kuhn, with silence. Even his superb autobiography, Out at Home, which published the year he died, failed to stir open conversation about homosexuality in sports. Practically no one in the sports-writing community would acknowledge that Burke was gay or report stories that followed up on his admission.
He told People magazine while promoting his book in 1995, "My mission as a gay ballplayer was the breaking of a stereotype ... I think it worked ... They can't ever say now that a gay man can't play in the majors, because I'm a gay man and I made it."
And yet Burke is remembered less today as a pioneer for gay rights and more as the man who, along with Dusty Baker, invented the "high five."

Wait, he and Dusty Baker invented the high five?  Wow, there is a whole lot of stuff I'd never heard of in this story.