The mob has always been big in drugs and especially heroin . East Harlem basically invented the dope trade .

It was sold pretty much out in the open until the 50s when the deal you die rule but as we all know this was BS and probably for public misinformation and possibly a way for the bosses to restrict this trade to their most trusted people . Now made guys were killed for dealing but other factors were probably in play .

Usually a family's big dealer(s) were people the boss could absolutely trust and is a reason why some of the mafias most successful members were dealers . John Oremento, Genovese , Galante , Casso , Conte, Gambino etc . However I really don't know any big Columbo wholesaler , but the Luchesse and Bonnano were neck deep in powder .

Today it's high end weed which actually has big margins and from a risk : reward standpoint is probably the wholesale biz to be in but there are still some big heroin wholesalers out there , I don't know who but somebody is still moving that Montreal product .