Centuries of chattel slavery, a century of overt de jure discrimination and segregation after slavery, and continued institutional discrimination by policies that do not correct for but instead perpetuate the effects of the earlier overt discrimination.
One (but not the most significant) direct effect of which was the alienation of the African-American community from institutions and the normalization of a culture of distrust of institutions, including the law,aw enforcement, schools, health systems, etc. (Some aspects of which are arbitrarily labelled “ghetto culture”.)