"Before Prohibition beckoned, our modern racketeers were small-shots at pocket-picking, lush-rolling, porch-climbing, safe-cracking and other form s of misappropriation of property... We see that racketeers and gangsters are not confined to any one race or class. In racketdom you will find Anglo-Saxons and Celts, Latins, Teutons and Semites and every conceivable blood strain. There is no nationalism in crime, just rugged individualism. Many racketeers spring from respectable families, many more are crooked in the womb. A few, a very few, stem from the wealthy and educated class; the majority are slum products, children of the tenements, the street corners, pool rooms, speakeasies and reformatories. Our slickest racketeers acquired their smoothness in prisons, which, as the phrase-makers have it, are nothing but schools for crime."
Click here to see a chart indicating the decreased murder rate following the repeal of Prohibition.
Another article on this topic can be read here
More about the 1920s mob can be read here...
An Al Capone article can be read here...