Actually, Jason Collins Isn't the First Openly Gay Man in a Major Pro Sport - Allen Barra - The Atlantic:
What Ayanbadejo didn't know was that one baseball player already had.
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