Two short years after 1968, the year the United States endured a series of cataclysmic episodes of politically tinged bloodletting, historian Richard Hofstadter observed that “Americans certainly have a reason to inquire whether…they are not a people of exceptional violence.”

Indeed, as ’68 brought shockwave after shockwave—assassinations, urban riotsand ugly news from the Vietnam War front—a fierce national debate buzzed: Was the United States a society far more prone to violence than all other industrialized nations? And if it was, what made it so? Fifty years later, the debate still rages.