of acts of Congress is a question for the federal courts, not the state legislatures. For example, Vermont's resolution stated: "That the General Assembly of the state of Vermont do highly disapprove of the resolutions of the General Assembly of Virginia, as being unconstitutional in their nature, and dangerous in their tendency. It belongs not to state legislatures to decide on the constitutionality of laws made by the general government; this power being exclusively vested in the judiciary courts of the Union." In 1800, the Virginia Legislature issued a report responding to the criticism of the Virginia Resolution. Madison wrote the Report of 1800. Madison affirmed each part of the Virginia Resolution, and again argued that the states have the right to interpose when they believe a federal law is unconstitutional. He explained that a state's act of interposition, unlike a judicial interpretation of the Constitution, has no legal effect. Rather, when the states interpose and declare a federal law unconstitutional, these declarations "are expressions of opinion, unaccompanied with any other effect than what they may produce on opinion, by exciting reflection. The expositions of the judiciary, on the other hand, are carried into immediate effect by force." Madison explained that the purpose of a state's declaration of unconstitutionality is to mobilize opposition to the federal law and to enlist the cooperation of other states. Madison said that the states might take various types of joint action to remedy the situation, such as jointly applying to Congress for repeal of the law, instructing their senators to submit a constitutional amendment, or calling a convention to propose constitutional amendments. During the Nullification Crisis of the 1830s, Madison further explained the concept of interposition as set forth in his Virginia Resolution. Madison denied that any single state had the right to unilaterally determine that a federal statute is unconstitutional. Madison wrote, "But it follows, from no view of the subject, that a nullification of a law of the U. S. can as is now contended, belong rightfully to a single State, as one of the parties to the Constitution; the State not ceasing to avow its adherence to the Constitution. A plainer contradiction in terms, or a more fatal inlet to anarchy, cannot be imagined." Rather, the interposition contemplated by Madison would be "a concurring and cooperating interposition of the States, not that of a single State." Madison argued that interposition would