You should look at photos of Blacks in DC just after the Civil War and compare them to today. You’re right the photos say a lot about the fall of Black culture and the race baiters who seduce them!
Before Uncle Sam made the black father unnecessary, they’d come a long way; unfortunately their trek northward to work in the factories coincided with the shuttering of those factories as jobs left our shores, and while the original immigrants did well the next generation dealt with the urban blight (and lost a chance at a middle class lifestyle).
I’d imagine the same thing would have happened if the Irish came here and the transcontinental railroad was already built and the Civil War was already over.