I recall seeing similar signs at the city limits of another small Texas town — but that was 60 years ago or so. IIRC, those may have even shared the same post with the city limits signs...
Everybody “remembers,” but not one single black civil rights person (even way back then) ever took a picture?
I’m calling this “false memory syndrome” at best, until I see pictures.
A Brownie camera wasn’t expensive, even then.
Even as an early teen, my thought at the time was, “The merchants in this town are stupid to drive away business...” It never made sense to me.