The article aims at revisiting some aspects of the work of Max von Seydel, a Bavarian constitutional law scholar who championed an interpretation of the Constitution of Bismarck's Reich not as "Bundesstaat" but, rather, as "Staatenbund". In so doing, it looks into a particular reading of German federalism, which has never been dominant but has coexisted with the one which highlights the unitary traits of the German "Bundesstaat". Also because of his intellectual debt to John C. Calhoun, Max von Seydel's legacy looks controversial and paradoxical at the same time.