“Two factors mark the major differentiation between earlier violent gangs and today’s violent gangs: the intensified commerce of drugs and the violence that surrounds the drug business, and the enormous increase in the availability of lethal automatic weapons that are used in gang murders.

—Lewis Yablonsky, Gangsters: Fifty Years of Madness, Drugs, and Death on the Streets of America

Gangs are not a new problem in the United States; they have existed in New York and other eastern cities for more than two hundred years. An examination of gang life in 1940s and 1950s New York and 1960s and 1970s Los Angeles helps explain the development of late twentieth-century gangs—gangs that scholars argue are far more violent than their mid-century predecessors.

Eric C. Schneider explored 1940s and 1950s gang life in his book Vampires, Dragons, and Egyptian Gangs: Youth Gangs in Postwar...