Dr. Daniel Hale Williams is often described as the first person to successfully perform an open-heart surgery. That's not entirely accurate, but he was still a surgical innovator, and he was also a huge part of the Black Hospital Movement.
Research:

Behind the Scenes Minis: Oh, Kropotkin!
17:28

Peter Kropotkin's Mutual Aid, Part 2
49:57

Peter Kropotkin's Mutual Aid, Part 1
45:03