Tension filled the air on the night of August 22, 1927. Italian immigrant anarchists Nicola Sacco and Bartolomeo Vanzetti were to be executed at midnight.

Nearly eight hundred police formed a “cordon of steel” to guard the state prison in Charlestown, Massachusetts, where the two men were held. Machine guns and searchlights lined the south and west walls of the death house. Authorities had gas and tear bombs at the ready. In nearby Boston, searchlights shone down from the State House roof. Police armed with guns positioned themselves at intervals between the lights. “It was,” according to the New York Times, “the first time in Massachusetts’s history that such a scene had been enacted.”

As midnight approached, thousands gathered on the Boston Common and Beacon Street. Police arrested 156 people among the crowd amassed for the “death watch” in front of the State House.