Interpretation of the US constitution that emphasizes the powers retained by individual states and minimizes those given to the federal government. The dividing line between state and national sovereignty was left deliberately vague in the Philadelphia convention devising the constitution 1787.
In 1832 South Carolina developed the doctrine of nullification, claiming the right to overrule federal laws against its own interests. The practice of slavery was claimed to be among a state's rights in the years leading up to the American Civil War, and the right to secede from the Union was claimed by those southern states forming the Confederacy at its outbreak. More recently, federal support for civil-rights campaigns during the 1950s and 1960s was sometimes inhibited by a reluctance to challenge states' rights.