had formed such a compact; if it were not true that the adoption of the Constitution was a mere alteration of the form of a political state already in existence; it would follow, as the Kentucky resolutions asserted, that each State had the exclusive right to decide for itself when the compact had been broken, and the mode and measure of redress. It followed, also, that, if the existence and force of the Constitution in a State were due solely to the sovereign will of the State, the sovereign will of the State was competent, on occasion, to oust the Constitution from the jurisdiction covered by the State. In brief, the Union was wholly voluntary in its formation and in its continuance; and each State reserved the unquestionable right to secede, to abandon the Union, and assume an independent existence whenever due reason, in the exclusive judgment of the State, should arise. These latter consequences, not stated in the Kentucky resolutions, and apparently not contemplated by the Virginia resolutions, were put into complete form by Professor Tucker, of the University of Virginia, in 1803, in the notes to his edition of "Blackstone's Commentaries." Thereafter its statements of American constitutional law controlled the political training of the South. Madison held a modification of the State sovereignty theory, which has counted among its adherents the mass of the ability and influence of American authorities on constitutional law. Holding that the Constitution was a compact, and that the States were the parties to it, he held that one of the conditions of the compact was the abandonment of State sovereignty; that the States were sovereign until 1787-8, but thereafter only members of a political state, the United States. This seems to have been the ground taken by Webster, in his debates with Hayne and Calhoun. It was supported by the instances in which the appearance of a sovereignty in each State was yielded in the fourteen years before 1787; but, unfortunately for the theory, Calhoun was able to produce instances exactly parallel after 1787. If the fact that each State predicated its own sovereignty as an essential part of the steps preliminary to the convention of 1787 be a sound argument for State sovereignty before 1787, the fact that each State predicated its sovereignty as an essential part of the ratification of the Constitution must be taken as an equally sound argument for State sovereignty under the Constitution; and it seems difficult, on the Madison theory, to resist Calhoun's triumphant conclusion that, if the States went into the convention as sovereign States, they came out of it as sovereign States, with, of course, the right of secession. Calhoun himself had a sincere desire to avoid the exercise of the right of secession, and it was as a substitute for it that he evolved his doctrine of nullification, which has been placed in the first volume. When it failed in 1833, the