By 1920, the forty-one-year-old Carlo Tresca was an immensely popular labor organizer — or, as Italian-American historian Nunzio Pernicone puts it, “indisputably the most important Italian radical in the United States.” Fiery, intelligent, and larger-than-life, Tresca was also an immigrant, arriving in New York in 1904 after leaving his hometown of Sulmona, ninety miles east of Rome. He was one of twenty million migrants from southern and central Europe who reached US shores between 1880 and 1920, an influx which prompted a nativist backlash and harsh new laws to limit immigration.

Tresca also arrived in the United States in a period of widening clampdowns on dissent, which especially developed during World War I. Democratic president Woodrow Wilson signed into law the Espionage Act on June 15, 1917, just before the United States entered the conflict, and then the Sedition Act on May 16, 1918, which further expanded the executive’s powers. Together, they gave authorities the power to deport or imprison anyone who criticized the war effort. “Wilson is still remembered as the president who repressed dissent more often and more harshly than any other occupant of the White House,” notes historian Patricia O’Toole, author of the 2018 book The Moralist: Woodrow Wilson and the World He Made.