The four-day Attica Prison riot begins, eventually resulting in 39 dead, most killed by state troopers retaking the prison.

The Attica Prison riot took place at the state prison in Attica, New York; it started on September 9, 1971 with a violent takeover of the prison control center in which one prison officer, William Quinn, was killed, and ended on September 13 with the highest number of fatalities in the history of United States prison uprisings. Of the 43 men who died, all but one guard and three inmates were killed by law enforcement gunfire when the state retook control of the prison on the final day of the uprising. The Attica Uprising has been described as a historic event in the prisoners' rights movement.

The New York State Police (NYSP) is the state police of the U.S. state of New York; it is part of the New York State Executive Department and employs over 5,000 sworn state troopers and 711 non-sworn members.

Attica Correctional Facility is a maximum security prison campus in the Town of Attica, New York, operated by the New York State Department of Corrections and Community Supervision. It was constructed in the 1930s in response to earlier riots within the New York state prisons.