This article aims to understand Carlo Cattaneo’s federalist theory along the path of his thinking which finally arrived at a vision of United States of Europe. It then tries to find some implications for the ideas of the European integration in Carlo Cattaneo’s federalism by focusing on the debate between Frigessi and Puccio surrounding the issue of defining his political theory and its significance. To this end it examines whether Cattaneo can be considered as the last Jacobin within the eighteenth century utopian reformism or the new Jacobin in the context of the nineteenth century capitalistic development. In doing so, this article proposes that he should be situated in the context of the currents of liberalism in Italian Risorgimento. Seen from this context, Cattaneo seems to have been a theorist of the liberty rather than a Jacobin. Furthermore, it shows that it can be interpreted that his federalism forms a federal-liberal moment in the ideas of the European integration. Surely, Cattaneo can be characterized so from his intransigent objection to the hegemony of the monarchy of Piedmont, his support of an alternative of federal Italy based on the regional self-rule, and his plan for the federal reconstruction of the European order as a condition for Italian unification. In addition, he tried to convince radical liberals and republican revolutionaries like Giuseppe Mazzini and Giuseppe Ferrari not to engage in secret conspiracies and revolutionary activities but to pay attention to the political education of the masses. And he argued that, only within smaller political units like regions and communes, the people could be informed quickly and effectively about issues which affected their lives and would find it easier to observe the work of their political leaders and officials. These arguments will be a good case to illustrate an agenda of the ‘democratic governance.’However, it is difficult to utterly dismiss the utopian and mythic ideas underlying his ideological and historical arguments as the residues of the eighteenth century thought. He did not evaluate the importance of nation as a unit for economic development and progress of civilization(incivilmento), emphasizing on the conceit of nations(boria delle nazioni). Indeed, he spoke little about Europe and United States of Europe. But validity of his federalism consists in a simple and consistent assumption, not in a concrete and operative plan: European federal reorganization must be formal and external, if not based on the principles of liberty and progress. An interpretative norm can be deducted from this assumption. The way for the European integration must be paved by means of all national and regional autonomy and self-government and engagement from bellow, not hegemony of powers and bureaucratic control. And Europe will be an obstacle to progress of civilization in case of launching its ethnic and cultural superiority, so-called the ‘conceit of Europe.’