The most definitive recent study was based on the US census and reported here: http://www.census.gov/prod/2012pubs/p60-243.pdf
With average household income greater than 32,000, and assuming a standard bell curve distribution, this puts 70% of african americans over the poverty line, the thresholds for which are here: https://www.census.gov/hhes/www/poverty/data/threshld/index.html
The number I did screw up on was the total number of african americans in the deoendent underclass which is closer to 16 million. My apologies for that, but I would still assert that 2/3rds of the nation’s 43 million african - american citizens are not dependent on the government for their food and housing.
We may quibble about defining “middle class”, but in my opinion, if you are not in poverty, that puts you somewhere in the middle or better.
Just because somebody is living in a crappy neighborhood, does not mean that they do not work and pay for their own stuff. I lived in some pretty sketchy neighborhoods in my younger days.