@zhivi, I'm curious if there might be a significant correlation between #SundownTowns of the mid 20th century and #WetTowns and #DryTowns of the late 19th and early 20th centuries viz. #Prohibition. My initial hunch is that more wet towns than dry ones are likely to have been sundown towns, mostly because of the strong connection between some abolitionist and prohibitionist groups.

For example, Pennsylvania: https://www.lcb.pa.gov/Licensing/Topics-of-Interest/Pages/Wet-and-Dry.aspx