Yes, yes, and yes.
For me personally, the letters column in Black Belt is one place where I saw a lot of the racism of the period would play out. But I also remember enough of it even from some of the articles as well.
To date, I *still* have one letter to the magazine saved to one of my files somewhere, written in the mid-70s by a Japanese gentleman who took serious umbrage at something another reader had previously written about the black presence in Asia, and the oft disputed blackness of Buddha. I'm pretty sure that the initial letter was written in response to some anti-black commentary found in a then recent history based article in the magazine.
The respondent was pretty ticked off and insulting as I recall. So much so that I wanted to write a response, even now 45+ years later (!!), just to underscore whatever truths that have subsequently been established which he and others like him were so deeply in denial of then.
My latent response would also serve to illuminate the casual and not so casual racism that African-Americans have always been targets of, and how martial arts mags like Black Belt had a deeply permissive hand in that culture.
As a related aside, that was one of the few (LOL) admirable things about the late Count Dante. Much to his credit, he was the only white due I can recall who wasn't afraid to talk about that elephant/element in the American martial arts world.