On September 9, 1971, inmates at the Attica Correctional Facility in upstate New York enacted the largest prison uprising in United States history, taking staff as hostages. After protracted negotiations and a five-day standoff, the New York State Police raided the facility with shocking brutality, leaving 43 dead, followed by vicious reprisals against survivors and then an elaborate cover-up. It was the bloodiest one-day clash on American soil since the US Civil War. Now, five decades later, when the country has the world’s highest incarceration rate, the story of what happened at Attica deserves fresh attention.