In June 1918, near the end of World War I, the Socialist Party of America’s presidential candidate, Eugene Debs, delivered a scathing antiwar speech to a crowd in Canton, Ohio.

Debs knew that he had to be careful in how he phrased his remarks, noting ironically that “it is extremely dangerous to exercise the constitutional right of free speech in a country fighting to make democracy safe in the world,” a reference to the Espionage Act that had been signed by President Woodrow Wilson the previous year, which made it a crime to criticize the draft.