In 1892, unrepentant anarchists Alexander Berkman, Henry Bauer, and Carl Nold were sent to the Western Pennsylvania State Penitentiary for the attempted assassination of steel tycoon Henry Clay Frick. Searching for a way to continue their radical politics and to proselytize among their fellow inmates, these men circulated messages of hope and engagement via primitive means and sympathetic prisoners. On odd bits of paper, in German and in English,...