In 1939, while preparing to fight his right to attend the segregated University of Missouri to practice law, Lloyd Gaines steps out to buy stamps on a cold rainy night and is never seen again.
Sources:
https://en.wikipedia.org/wiki/Lloyd_L._Gaines
https://calendar.eji.org/racial-injustice/mar/19
https://scholarship.law.missouri.edu/gaines/
https://historicmissourians.shsmo.org/?page_id=6877
https://www.riverfronttimes.com/news/the-mystery-of-lloyd-gaines-2479115