The Business of Crime: Italians and Syndicate Crime in the United States by Humbert S. Nelli

"Dr. Nelli . . . describes the kinds of crime that prevailed in Italian immigrant enclaves in America; like most American crime, then as now, Italian crime was one aspect of the so-called culture of urban poverty—boys graduated from street gangs to criminal gangs. None of these gangs were very big until Prohibition brought the Great Leap Forward, to a level that Dr. Nelli calls 'entrepreneurial crime.' His fine account makes sense of many murderous incidents, differentiates among places, and sketches individuals and the talents (Torrio's brains, Capone's brutality) that enabled them to rise in the underworld."—New Yorker "A definitive history of organized crime in America."—American Historical Review