Urban Crime and Criminal Justice: The Chicago Case

The Journal of American History reports on organized crime and the union movement:

The strength of the criminal underworld lay in the fact that its members
were not outsiders. They could frequently maintain mutually satisfactory, if
sometimes ambiguous, relations with enforcement officials. They were tied
to politics by a shared belief that the system should operate on the basis of
friendship and favors. They played a part in organized labor and in many
aspects of business activity.

A journal article well worth your time.