The author briefly analyses the roots of the American Federation and the initial struggle between Federalists and Anti-Federalists concerning the autonomy of the states and the subsequent ratification of the Constitution. He also emphasizes the influence of Hamilton’s ideas on the Chief Justice John Marshall’s opinions in the interpretation of the Constitution, its Amendment n. 10 and the so termed “Dormant Commerce Clause” and “Supremacy Clause”. He also studies the later repercussions of these theories on the Republican Brazilian Constitutions.