We have, thanks in large part to slavery and to liberal big-government programs, very little in the way of historic record of blacks’ being left to stand on their own and demonstrate it.
This is incorrect. The so-called "race films" of the '40's and early '50's, which were produced by black producers and directors using almost all black talent, without the taint of PC/Communist meme-grinding, showed intact black society before the malefic influence of orthodox liberalism began to maim and poison it. The films, moreover, were shot in black parts of real American cities and towns, so that real black society supplied the mise en scene and "atmospheric specialists" </off jargon> (extras).
Most of white society had never heard of these films when Roger Ebert limelit a previously specialist interest in old films on his TV show about 12 years ago.
You mean, when Jim Crow and other measures were still in place.