The Haymarket Martyrs
(left column)
August Spies (1855-1887)
Albert R. Parsons (1848-1887)
Adolph Fischer (1858-1887)
George Engel (1836-1887)
(right column)
Louis Lingg (1864-1887)
Samuel Fielden (1847-1922)
Oscar Neebe (1850-1916)
Michael Schwab (1853-1898)

During a mass labor meeting on May 4, 1885, in Haymarket Square, a bomb thrown at the legs of the police in an unexplained manner provided the necessary pretext for arrests. Eight leaders of the revolutionary and libertarian socialist movement were arrested, seven of them sentenced to death, and four subsequently hanged (a fifth committed suicide in his cell the day before the execution). Since then the Chicago martyrs-- Parsons, Fischer, Engel, Spies, and Lingg-- have belonged to the international proletariat, and the universal celebration of May Day (May 1) still commemorates the atrocious crime committed in the United States.
(From Anarchism by Daniel Guerin)