Popular sovereignty is a doctrine rooted in the belief that every citizen is sovereign, and rather than a monarch or single individual, that they could unite and each delegate a portion of their sovereign powers and duties to those who wished to temporarily serve as officers of a state, who would serve according to the will of the people. In the United States, the term has been used to express this concept in constitutional law. It was also used during the 19th century to refer to a potential resolution to the debate over the expansion of slavery into the territories, which argued that the inhabitants of a territory, rather than Congress, seeking statehood should decide whether or not slavery would be permitted.
The idea that the people were sovereign (often linked with the concept of the consent of the governed) was not developed by the Americans. Rather, the consent of the governed and the idea of the people as a sovereign had clear 17th and 18th century intellectual roots in European history. The American contribution lay in how they put these ideas into practice. Before the American Revolution, few examples existed of a people deliberately creating their own governments. Most people in the world experienced governments as an inheritance—whether monarchies or expressions of raw power.
Revolutionary Americans created an independent government that was explicitly premised on popular sovereignty. The American Revolution marked the establishment of the concept of popular sovereignty in large-scale practice as it had been discussed and experimented with in the European historical contexts. With their Revolution, Americans substituted the sovereignty of a monarch with a collective sovereign composed of the people. Henceforth, early Americans supported the principle that governments were legitimate only if they rested on popular sovereignty – that is, the sovereignty of the people.
After the Revolution, the idea of the people as the sovereign both unified and divided Americans in thinking about government and the basis of the Union; with questions being raised over what the precise meaning, permissible actions and will of a collective sovereign was. In 18th-century European political thought, "the people" excluded most of the population, such as women, slaves, indentured servants, those lacking sufficient property, indigenous people, and children. This conception was reflected in the early American republic by the disenfranchisement of women and those lacking sufficient property and the exclusion from citizenship and naturalization of slaves and other non-whites. Historian Ronald Formisano notes that "assertions of the peoples' sovereignty over time contained an unintended dynamic of raising popular expectations for a greater degree of popular participation and that the peoples' will be satisfied."