Youthful street gangs have become a seemingly ineradicable fixture of American urban life. Stories abound of well-armed black or Latino teenagers locked in heated battle, often to the death, with their rivals, growing rich off the profits of drug dealing, and swelling the ranks of already overcrowded state prisons. By the end of the twentieth century, as hysteria over the existence of these gangs increased, a sort of historical amnesia appeared to take hold of the press and the general public. It is easy to forget—or so it would seem—that the existence of gangs has been a consistent social phenomenon since the nineteenth century, causing sociologists to lock horns in debating the origins and motivation of the street gang. Common sense, however, dictates that any group, such as deprived inner-city youth, excluded from the general prosperity, will compensate for deprivation by staking a claim to their...