After World War I ended, Eugene Jacques Bullard returned to Paris. He worked as a jazz drummer and nightclub owner, and as the tensions that led to World War II loomed, as an intelligence agent for France.
Research:

Robert Moses and the Shaping of New York, Part 2
42:12

Robert Moses and the Shaping of New York, Part 1
41:59

SYMHC Classics: Eradication of Smallpox
43:25