The Sacco-Vanzetti affair is the most famous and controversial case in American legal history. It divided the nation in the 1920s, and it has continued to arouse deep emotions, giving rise to an enormous literature. Few writers, however, have consulted anarchist sources for the wealth of information available there about the movement of which the defendants were a part. Now Paul Avrich, the preeminent American scholar of anarchism, looks at the...