It is necessary to reconcile the precious substrate provided by the foundations of classical theories with the growing demands of an international society in a process of crisis and rapid and intense mutation - as the borders of nation states are increasingly blurred by the power of globalising economic and technological forces. With this in mind, the research published here found a fascinating and rich historical scenario in the War of Secession in the United States of America, where relevant political, constitutional and international dilemmas experienced by the young nation born in 1776 were analysed - dilemmas that also hang over politically organised societies. Starting with the Unionist maritime blockade of 1861 (one of the measures issued during the ’Lincoln Dictatorship’), the Prize Cases of 1863 were studied - analyses that entered into the doctrinal framework of Carl Schmitt (State of Exception), enriched with the doctrinal ponderings of Alexander Hamilton and Clinton Rossiter. This work is particularly aimed at the areas of International Relations, Defence and Security, History, Political Science and Constitutional Law.