The “culture” is a result of LBJ’x War on Poverty. Previous to that the blacks had been making rapid gains across the population tha got going in the Depression and accelerated in WWII as rural southerners migrated in large numbers to the northern cities to take jobs in factories. During the War Negros who were not really welcome into the military took many jobs that whit men left to go to war. They became skilled and the Negro population entered a phase analogous to the Irish and Italian mass migrations of earlier generations. It was ongoing into the 60s when Johnson’s War on Poverty that pretty much ended marriage as it paid new payments to women who had children and no husband.
1960 U.S. Census: 3% white births out of wedlock, 30% black births
2010 U.S. Census: 30% white births out of wedlock, 72% black births
(2025-1965)/17 years per generation = 3.5 generations