There was a huge study that came out a couple of years ago, led by the Harvard economist Raj Chetty. He found that two of the biggest predictors of low upward mobility were 1) living in neighborhoods with concentrated poverty and 2) growing up in a neighborhood with a lot of single mothers.
3/4 of black children or more are illegitimate and come from families where this has been the norm.
Nor can blacks blame illegitimacy and the intergenerational poverty it creates on whites, because it is a historically new phenomena.
From black Ivy League researcher Walter Williams:
Academics teach that the breakdown of the black family is the legacy of slavery and discrimination. They ignore the following facts. In 1950, 72 percent of black men and 81 percent of black women had been married. Also, only 17 percent of black children lived in single-parent households; today it’s close to 70 percent. Every census from 1890 to 1950 showed that black labor force participation rates exceeded those of whites. During the late 1940s, the unemployment rate for black 16- and 17-year-olds was less than that for white teens.
http://jewishworldreview.com/cols/williams090716.php3#F1SWXCDK7VcHHTGs.99
TLDR - welfare and black leaders saying sign up for it as reparations destroyed the black family in the 1960s and stalled improvement in those communities, and then they blame whites for it.