Heroin (and meth) were always constants in some hoods in Philly, but crack really swept through and became the drug of the streets here in the late 80s/early 90s. Now it seems like heroin (really fentanyl) is back in that #1 spot, especially if you add-in all with all the opiod pills.

Always wondered why I didn't see more crack on The Wire (not that that show is a real source of info, just something I noticed).