My current residence's sundown-town status is now pretty well known via a long-running one-man show highlighting the point, followed by a book. Now it's pretty rainbow. (It was also reported on as exemplar from time to time in national media in the late 60's and early 70's, though I bet that was memory-holed quick.)
There's a structure like a miniature triumphal arch, with statuary underneath it, in the middle of the main drag at the city limit where it turns into a super-disinvested Black area. Right where the police used to patrol for wanderers-across. I assume there's some connection.
I checked Wisconsin and the list seemed to include virtually every town apart from Madison and Milwaukee, which is trivially easy to believe -- but many of them are just listed as "Possible" without further information. The entry for Appleton was interesting/depressing. I think I've told the story before about my horrified parents getting the racial covenant taken out of the deed to my childhood home (in Madison): the realtor waved it away, "no one will hold you to that," but my parents refused to sign anything until it was removed, retold the story for years, and remarked sadly that the neighborhood still really didn't welcome people of color at all. (They were okay raising a family there. I would have looked for a different neighborhood, so I guess there's your glacial generational progress at work? Or not? I don't know if my own hand-waving "let the horrible white people segregate themselves in their horrible communities" attitude is meaningfully better. Entirely unsure if my childhood neighborhood would qualify as "horrible" by my current standards. This makes me sad; also I miss the oak trees.)
This database is kinda nonsense, it looks like there's not a lot of quality control, and a lot of the listed towns are listed as "possible."
For example, this entry is unhinged and written by someone with no knowledge of local history: https://justice.tougaloo.edu/sundowntown/york-county-pa/
(Yes York had serious and important race riots, but those involved attacking the substantial Black population who lived there both before and after the riots. Has nothing to do with being a sundown town. And historically the bulk of the York black population comes from South Carolina, not Maryland.)
Now I'm sure there were sundown towns in York, Hannover and Camp Hill are listed with some possible evidence (but very vague). Conversely there's nothing about the places I think of as the most traditionally racist (e.g. Red Lion, Dallastown, Dover).
Here's a good one -- https://justice.tougaloo.edu/sundowntown/grosse-pointe-mi/
"'The most desirable neighborhood for the raising of children, according to these Grosse Pointe real estate dealers and brokers,' Rabbi [Leon] Fram said, 'is one in which the children shall never see a Negro except in the role of a porter or a shoe shine boy, never encounter any human being who believes in a faith other than Christianity, never hear a foreign accent.' He quoted the minister of a Grosse Pointe church as stating that 'Jesus Christ could never
qualify for residence in Grosse Pointe.'"
-"Klan Standards Prevail in G.P., Rabbi Charges",
Detroit News, 14 May 1960
https://justice.tougaloo.edu/sundowntown/royal-oak-mi/
I went to a Royal Oak elementary school in the early 1970s. If I'm remembering correctly (not a sure thing at all) everyone was white, and every Jewish kid came from Huntington Woods (in the mid-70s Huntington Woods kids were switched to a different school district).
That's why John Cusack turned out all murdery.
Here's one you probably recall Moby
https://justice.tougaloo.edu/sundowntown/upper-arlington-oh/
A Columbus suburb close to The University -- lots of faculty and administrators live there.
My first boss lived there. I lived near it, but in Columbus proper (Dierker).
White Settlement, Texas, we just don't know if this was a sundown town
https://justice.tougaloo.edu/sundowntown/white-settlement-tx/
The status of White Settlement, Texas is currently listed as "possibly" a sundown town
https://justice.tougaloo.edu/sundowntown/white-settlement-tx/
The status of White Settlement, Texas is currently listed as "possibly" a sundown town
You never know. I heard that Sodom the town really wasn't into butts.
I was doing some searches on newspaper.com for my mid-sized NE Ohio city circa 1960 and which returned a lot of real estate ads. On every page of ads there was invariably several ads which prominently said "Colored or White." Expanding the time period, the trend seemed to rise slowly from the 40s through the early 60 and then declined precipitously in 1964 and were gone in 1965. Also somewhat fewer but still a fair number of "colored Preferred" following the same pattern (although from a sampling earlier ones were of then help wanted ads). I assume the much greater number of unmarked ads were presumed to be "white only"? Not sure. I believe redlining extended into the '70s (and continues informally until today).
Speaking of newspapers.com, it can be a pretty useful resource, but also a bit pricey. My daughter have used it on or off for genealogical stuff. Have it right now. Anyway, if someone has a burning question that they think can be answered from old newspapers (they have a lot in their collection, not the biggest ones like the NYT, but many others) feel free to reach out to me at the linked email.