Google image search *South Bronx 70s* - it looks like Germany after WWII. And it surely didn't look much better in Harlem etc. At that time there were people starving - in NYC. There were districts where nine out of ten died an unnatural death, from murder, overdose, rat bites, etc.
The transformation NYC went through has to be one of the most impressive the world has ever witnessed. Interestingly, other parts of the US took the exact opposite route. Detroit was once the greatest manufacturing city in the entire world, today half of its population is "functionally illiterate" (not making that up...).