Nixlificatioiv, the refusal of. a state to permit an act of the federal congress to be executed within its limits. The Kentucky resolutions of 1798 declared the constitution to be a compact; that "to this compact each state acceded as a state, and is an integral party; that the government created by this compact was not made the exclusive or final judge of the powers delegated to itself, but that, as in all other cases of compact among parties having no common judge, each party has an equal right to judge for itself, as well of infractions as of the mode and measures of redress." To this it was added by the resolutions of 1799 that " a nullification by those sovereignties [the states] of all unauthorized acts done under color of that instrument [the constitution] is the rightful remedy." The election of Mr. Jefferson to the presidency in 1800 took away all occasion for any more distinct assertion of the doctrine at that time; but in the controversy over the tariff near the close of the administration of John Q. Adams, Virginia reasserted the right of each state to construe the federal constitution for itself; and in 1832 South Carolina undertook to give the doctrine practical effect by an ordinance adopted by a delegate convention chosen for the purpose, which declared the tariff acts of congress to be null and void, forbade the collection of duties within the state, required all persons holding office under the state to take an oath to support the ordinance on pain of vacating their offices, pledged the people of the state to maintain the ordinance and not to submit to force, and declared any acts of the general government to enforce the tariff or to coerce the state to be inconsistent with her longer continuance in the Union, and that she would forthwith proceed to organize a separate government.

This ordinance was met by a proclamation of President Jackson in which he declared that "the power to annul a law of the United States, assumed by an individual state, is incompatible with the existence of the Union, contradicted expressly by the letter of the constitution, unauthorized by its spirit, inconsistent with every principle on which it was founded, and destructive of the great objects for which it was formed," and pledged himself at all events to execute the laws. This threatening controversy was for the time allayed by the compromise of Mr. Clay; but when dissatisfaction with federal affairs again led to its practical assertion, the states did not stop at the nullification of particular laws, but proceeded at once to declare their relations with the Union at an end. (See Calhoun, John C.; Clay, Henry; Hayne, Robert Y.; Jackson, Andrew; and Wehster, Daniel. See also Confederate States).