Second source with date is a newspaper:
Monroe Baker, Mayor of St. Martinsville, LA (1867, two years after the Civil War) he was a free person of color before emancipation. Other source (in body) says it was on October 5
Submitted 11 months ago by TheOneWithTheHair@lemmy.world to history@lemmy.world
https://www.newspapers.com/article/25167601/monroe_baker_mayor_of_st_martinsville/