From 1864 to 1876, socialists, communists, trade unionists, and anarchists synthesized a growing body of anticapitalist thought through participation in the First International—a body devoted to uniting left-wing radical tendencies of the time. Often remembered for the historic fights between Karl Marx and Michael Bakunin, the debates and experimentation during the International helped to refine and focus anarchist ideas into a doctrine of international working class self-liberation.

Robert Graham has been writing about anarchism for thirty years. He recently edited the three-volume collection Anarchism: A Documentary History of Libertarian Ideas.