I do know about Jews in the civil rights movement--several groups, like Unitarians, were disproportionately active then, and Jews were among them, though there were, of course, conservative Jews on the side of segregation too. My family was a small part of the movement in Florida. I appreciate the cop story, but it sounds like basic harassment--I was called both a n*gg*r and a n*gg*rl*v*r for speaking up, but no one thought I should have to use the "colored" facilities.
You're very right about the truth disappearing. I recommend this book by Adolph Reed: https://www.amazon.com/South-Jim-Crow-Its-Afterlives/dp/1839766263/ref=asc_df_1839766263/?tag=hyprod-20&linkCode=df0&hvadid=532660552781&hvpos=&hvnetw=g&hvrand=6542842567186633302&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9019659&hvtargid=pla-1393338289575&psc=1