Richard W. Clary’s lecture addresses the model of federalism adopted by the United States of America in its Constitution, written in 1787 and ratified in 1788, with key amendments relating to federalism in 1791 and 1868.  The Constitution simultaneously created a national government that operated directly on the citizens of the United States and a federal government that related to the then 13 (now 50) sovereign states.  The Constitution has been described as having “split the atom of sovereignty”, with two layers of government – one national layer, one multi-state layer – having different roles to play in the lives of their mutual citizens.  It replaced what had been thirteen independent states working together in a “firm league of friendship” with a fully functioning national government, thus succeeding in building a national identity while still preserving state sovereignty.  However, because the Constitution was the result of negotiated compromises between the “Federalists” and the “Anti-Federalists”, there was ambiguity in the overlapping spheres of national and state sovereignty.  Thus, the keystone on which this model of federalism rested was – and still is – the role of an independent national (federal) judiciary exercising robust judicial review of legislative and executive acts at both the national and state levels, with the Constitution and national (federal) law being the “supreme law of the land”.  The U.S. Supreme Court thus became the final arbiter in the continuous tug of war between the national (federal) and state governments over the line of demarcation between their respective spheres of power and authority.  The Founders in creating this American model of federalism recognized there would be conflicts but envisioned what has been characterized as a “spirit of federalism” – mutual forbearance and self-restraint, political cooperation and accommodation – that is being tested in the highly partisan environment that currently prevails in the United States.