"What is this book?" asks Joseph Déjacque at its beginning of his Humanisphere. His answer was that it "is not a literary work, it is an infernal work, the cry of a rebel slave." Just so. Those seeking fine literature would be well advised to do so elsewhere. This is the voice of an intelligent and literate nineteenth century workingman. After becoming a minor leader in the European revolutionary movements that culminated in the uprisings of 1848-1849, Déjacque participated in émigré circles across the channel in England and across the Atlantic in the United States. His experience shaped a unique contribution to radical internationalism in the nineteenth century.