You can read the primary historical sources and decades of public statistics for yourself. You can walk down the streets of West Baltimore, West Philadelphia, Anacostia, the south side of Chicago, or Northwest Milwaukee on your own and see what has become of those environments. The prior inhabitants of those areas managed to create thriving, safe neighborhoods without youth centers, constant media pandering, or massive public wealth retribution.
Recognizing the truth of history is of course distinct from blaming entire ethnic groups wholesale.