I don’t know about Harlem, but pre 1967 you felt very safe in Detroit. Believe it or not.
Actually, if you watch “documentary style” movies of the black experience before the Great Society, you will notice a relatively intact black family and much more of a “can do” attitude than today.
But it’s not really rocket science. Also, the stats are all out there. There was simply not the same hatred against whites.
That said, there were still plenty of whites that hated blacks. The KKK was still fairly strong, though I speak from my studies as opposed to personal experience. I never lived in an area where the KKK was all that big, or even apparent.
The whole “black culture” grew out of the democrats need for division. Prior to that, blacks and whites lived very much the same. Sure there has always been racism but blacks and whites could spot it and avoid going where they weren’t welcome.
Forced desegregation has been really bad for America. That’s not to say that I think segregation is good only that forcing contact creates tension.
Summer 1967 was the "long hot summer of discontent". It seemed like every major city in the US had race riots. I have to believe that all that anger had been simmering for a long time as a build up to the boil over that year. I can't speak to the streets of Harlem but I was attending college '63 to '67 in downtown Milwaukee and never felt threatened. As a student I used city buses or walked wherever I needed to go for three years before I acquired a car and moved to a southeastern suburb of MKE.