On May 4, 1886, a bomb was detonated at a peaceful worker’s protest meeting in Chicago’s Haymarket Square, killing seven policemen and wounding a larger number of civilians. No one has ever discovered who threw the bomb, though two scholarly studies of the Haymarket calamity by the late historians Paul Avrich and Henry David, each had their favorite candidate.

It was a momentous event in the bitter battles between labor and capital after the Civil War when working people, many of whom were immigrants from Germany and Eastern Europe, tried to organize unions and humanize their labors while corporate owners, backed by the courts and federal and local governments, tried and generally succeeded in smashing their peons’ rebellions. The bloodletting at Haymarket effectively castrated the anarchist movement, but it also virtually eliminated the more moderate Knights of Labor and further empowered tycoons such as Cyrus McCormick and George Pullman and their unyielding political and judicial allies. “It is clear,” writes James Green, professor of labor history at the University of Massachusetts Boston in this thorough and acute chronicle of the Haymarket tragedy, that the bombing and subsequent trial of Haymarket suspects “should be read as a warning to citizens who allow the civil liberties of immigrants to be violated in the name of fighting terrorism.”

The demand for an 8-hour day was the central theme for working people. The owners of industry fiercely resisted 8-hours preferring 10 hours, six days a week. They responded to strikes and efforts to organize unions with killings, blacklists, firings, and reductions of wages. They hired the ubiquitous Pinkertons, and availed themselves of local police, federal troops, the National Guard and the courts to battle the extreme class divisions that had emerged in the wake of the swift growth of mass industrialization. Moreover, European dreams of anarchism and socialism, which arrived with many newcomers, terrified them.

After the bombing in Haymarket Square demands for revenge and punishment were stoked by the local press and opportunistic and reactionary politicians. The trial of the indicted men, presided over by a biased judge, was less than fair. Testimony favorable to the defendants was ignored and manufactured evidence favored, leading to inevitable guilty verdicts and the death penalty for four men. Two defendants received lengthy prison sentences and one committed suicide in his prison cell.

What developed among far too many Americans was a form of mass paranoia against “Reds”—a phenomenon that reappeared with devastating regularity in the 20th Century. The most prominent among the Haymarket defendants were Albert Parsons, a Confederate veteran and anarchist who sided with ex-slaves during the Reconstruction era and whose black wife Lucy fought for decades after his death to rehabilitate his reputation, later joining the Socialist Party and composing his biography. Parsons had no record of violence. But another defendant, August Spies, German born, a longtime supporter of the 8-hour day was also a revolutionary. Green quotes one of his speeches in which he tells his audience “you have endured the pangs of hunger and want; you have worked yourself to death; your children you [sic] have sacrificed to the factory lords…destroy the hideous monster that seeks to destroy you. To arms, we call you. To arms!”

Which, given their history in Europe, proved to be part of the problem facing American anarchists in general and the defendants in particular. The more violent their rhetoric became, the more they incited opponents to commit even more violent acts.

How, then, to battle the awesome power of corporate and state power, especially when employees had little or no rights and certainly no safety nets? Some have written in defense of embattled working people in that pitiless age that anarchists wished to give birth to a more moral world. The problem was what, specifically, was that new world and how best to reach it? And more specifically, what was the best way to attain an 8-hour day and the right to belong to unions? Was Bakunin, Berkman and Johann Most’s approval of violence the model or Kropotkin’s, the socialist Debs or even the accomodationist Samuel Gompers?

In time, however, the tide turned. It was too late for the dead police and anarchists but Illinois Governor John Peter Altgeld pardoned the two remaining Haymarket survivors in 1893, and accused the presiding judge of “malicious ferocity.” Excoriated by many but also widely defended, the courageous and principled Altgeld, whose future political career was permanently damaged, “feared that when the law was bent to deprive immigrants of their civil liberties,” comments Green, “ it would later be bent to deprive native sons and daughters of theirs as well.”

This remains wise advice in our own very troubled time.