NPR just posted up an interview with 91-year-old Bob Motley, who is the last living umpire from the Negro Leagues*.
It's an interesting item to listen to, especially for one fascinating detail: It's pretty common sports knowledge that Jackie Robinison broke the color barrier for players in 1947. But it took nearly two more decades before Major League Baseball had its first black umpire.
I won't spoil much else about it. Go listen to it now.
* When they say Negro Leagues, I'm personally assuming (not sure) that they are referring to the "major" Negro Leagues based on quality of play, which from the early 30s through intergration were the Negro American League and Negro National League.