Integration:Lead to black businesses collapsing as blacks were happy they could finally shop at white stores. Blacks felt that the white man's water was just that much colder so they patronized white businesses. Blacks also felt better working for the white man than other blacks.
White Flight: A lot of blacks felt comfortable working in factories for whites and not getting an education. In fact a lot of blacks that had educations had a hard time getting positions that required their degrees, so the incentive to get an education was lacking. Blacks also decided to live in the cities where they worked, which lead to whites fleeing the city to the suburbs, taking their businesses and infrastructure with them. That lead to areas being blighted. Redlining and block busting added to the table
War on Drugs: With the then absent infrastructure, the economics in the black community were lacking. Factory jobs became outsourced so uneducated blacks had even fewer options. A lot decided to sell drugs. Then came Reaganomics which had black men doing 20 year sentences for selling drugs... non violent crimes mind you.
Family Structure Decay: All while this is happening, the idea of family structure and manhood are being destroyed. Since a lot of black men couldn't be men in the traditional sense, they decided to become the b*stardized version of men. Gangsters and drug dealers. Family? That's thrown away at this point. Hell it was steadily being thrown away prior to this point, but the war on drugs was somewhat of the event horizon. Education was no longer valued. Swag was another way for black men to overcompensate for their lack of economic power.
Street Culture Promotion: Then came the cherry on top. The white man saw how black men valuing drugs and swag kept black men complacent so whites decided to promote "black hyper-masculinity". Black men favored valuing how big their dikks were, how great they could dance, how well they could rap, how much game they had and how many bytches they could fukk. This was made worse when white people allowed hiphop to become mainstream. Young black boys thought that the only way to get out of the hood was by picking up a basketball, a microphone or a bag of drugs. NOT by picking up a book.
Basically you want to know what happened to the culture? Lack of economics. You want any community to change overnight, take away their economics. This is why I laugh at people who say that in order to get out of the hood you need to "get right with God" or "find knowledge of self" or "have swag." White people didn't take love, God, swag, or knowledge of self out of the black community, but they damn sure took away the money.
The damage has been done. White people don't have to discriminate against blacks ever again. The mentality has been passed down by generation to generation. Whites could fall off the face of the planet and as long as the mentality and culture are the same it will never get better.
Needless to say, it was very systematic.
when immigrants don't assimilate. 
