The Kentucky and Virginia Resolutions were political statements drafted in 1798 and 1799 in which the Kentucky and Virginia legislatures took the position that the federal Alien and Sedition Acts were unconstitutional. The resolutions argued that the states had the right and the duty to declare unconstitutional those acts of Congress that the Constitution did not authorize. In doing so, they argued for states' rights and strict construction of the Constitution. The Kentucky and Virginia Resolutions of 1798 were written secretly by Vice President Thomas Jefferson and James Madison, respectively.

The nullification crisis was a sectional political crisis in the United States in 1832 and 1833, during the presidency of Andrew Jackson, which involved a confrontation between the state of South Carolina and the federal government. It ensued after South Carolina declared the federal Tariffs of 1828 and 1832 unconstitutional and therefore null and void within the sovereign boundaries of the state. However, courts at the state and federal level, including the U.S. Supreme Court, repeatedly have rejected the theory of nullification by states.