Definition
A citizen is a person who holds membership in a political community — a nation, state, or other organized civil society — and enjoys the full bundle of rights and bears the corresponding obligations that membership confers. In American law, the term operates at two distinct levels and must be analyzed separately for each context.
1. National citizenship. A person who owes allegiance to the United States and is entitled to its protection and to the full privileges and immunities guaranteed under the Constitution. National citizenship is acquired by birth on U.S. soil (jus soli), birth abroad to a citizen parent under qualifying conditions, or naturalization. The Fourteenth Amendment (1868) settled the foundational rule: all persons born or naturalized in the United States, and subject to its jurisdiction, are citizens of the United States.
2. State citizenship. A person who is domiciled within a particular state and entitled to that state's privileges and immunities. For purposes of federal diversity jurisdiction, citizenship is determined by domicile — a person's true, fixed home with the intention to remain — not merely by physical presence or residence.
3. Derivative and functional uses. "Citizen" appears as a term of art in specific statutory schemes. "Citizen suit" provisions in environmental and administrative statutes designate standing to sue in the public interest, extending to persons and sometimes to entities who are not aliens. In campaign finance law, the constitutional status of "citizen" versus "corporation" has been a site of significant doctrinal dispute.
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Common Language
Modern common usage (Wiktionary): A personal title denoting citizenship, implicitly of the nation in which it is spoken.
Historical common usage (Webster's 1913): One who enjoys the freedom and privileges of a city; a freeman of a city, as distinguished from a foreigner. Also, an inhabitant of a city; a townsman. More broadly, a person, native or naturalized, who owes allegiance to a government and is entitled to its protection.
The common meaning tracks national citizenship reasonably well, but the legal meaning diverges in two directions that matter for research. First, the law insists on distinguishing national citizenship from state citizenship, a distinction ordinary usage collapses entirely. Second, legal citizenship is a status with precise doctrinal tests — particularly domicile for diversity purposes — that the everyday sense of "inhabitant" or "resident" does not capture. A person can be a U.S. citizen and yet not be a "citizen" of any state for federal jurisdictional purposes (stateless persons, U.S. territories), or can be domiciled in a state without being a citizen of the United States at all.
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Common Confusion
CITIZEN vs. RESIDENT vs. DOMICILIARY: These terms are not interchangeable. A resident is simply present in a place, possibly temporarily. A domiciliary has established a permanent home there with intent to remain. A citizen (in the national sense) holds allegiance and constitutional status. For federal diversity jurisdiction, the operative concept is citizenship-as-domicile, meaning a permanent resident alien is not a citizen of any state for jurisdictional purposes, even if long resident there. Researchers encountering diversity jurisdiction disputes should not assume residence establishes citizenship.
CITIZEN vs. NATIONAL: A U.S. national owes permanent allegiance to the United States but does not hold full citizenship. Persons born in certain U.S. territories have historically held national status without citizenship. The distinction is largely obsolete for most U.S. territory residents today but remains relevant in immigration and passport law contexts.
CITIZEN vs. SUBJECT: Pre-revolutionary English sources, and some early American materials, use "subject" where American law uses "citizen." The shift is substantive, not merely stylistic: a subject owes personal allegiance to a sovereign; a citizen holds rights against the state as a member of a self-governing polity. Burrill's and Bouvier's bridge this transition and may use both terms in ways that can mislead if read without attention to the date and jurisdiction of the source.
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Core Elements
For national citizenship by birth:
- Born or naturalized in the United States
- Subject to the jurisdiction of the United States (excludes children of foreign diplomats; the scope of this clause is contested as applied to other categories)
For state citizenship (diversity jurisdiction):
- U.S. citizen (or, for aliens, a distinct analysis applies under 28 U.S.C. § 1332)
- Domiciled in the state — physical presence plus intent to make it a permanent home
For naturalization:
- Lawful admission for permanent residence
- Continuous residence and physical presence requirements
- Good moral character showing
- Attachment to constitutional principles
- Oath of allegiance
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Recognized Forms
/SUBTYPES
Natural-born citizen: A person who is a citizen at birth, without naturalization. The Constitution reserves the presidency and vice presidency to natural-born citizens. Whether birth abroad to a citizen parent satisfies this requirement is a long-debated question that historical dictionaries address incompletely and that remains technically unresolved by any court of final authority.
Naturalized citizen: A person who acquires citizenship after birth through the statutory naturalization process. Entitled to essentially all rights of natural-born citizens except eligibility for the presidency and vice presidency.
Citizen of a state (diversity): Domiciliary citizen for federal jurisdictional purposes. A corporation is deemed a citizen of its state of incorporation and the state where its principal place of business is located — a rule that has no analog in the historical citizenship concept.
Citizen-plaintiff (statutory): A person or entity authorized to bring a citizen suit under environmental, consumer protection, or other statutes that create private rights of enforcement in the public interest.
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Why It Matters in Research
The term carries different content depending on what legal question is being asked, and conflating its meanings is a persistent research error. A researcher working on a diversity jurisdiction problem needs citizenship-as-domicile doctrine, not the Fourteenth Amendment analysis. A researcher working on constitutional eligibility needs the natural-born citizen clause and its sparse interpretive record. A researcher working on environmental enforcement needs the citizen suit provisions and their standing requirements, which import their own definition of who may sue.
Historical sources require particular caution. Pre-Fourteenth Amendment materials reflect a world in which Black Americans were not citizens under federal law (a position Dred Scott v. Sandford, 60 U.S. 393 (1857), made explicit), women's citizenship was in various respects derivative of their husbands', and state citizenship was the primary locus of civil rights. The Fourteenth Amendment restructured this entirely, and sources published before 1868 — including early editions of Bouvier's — describe a citizenship regime that was constitutionally superseded. Even post-amendment sources from the late nineteenth century may not fully account for subsequent doctrinal evolution.
For jurisdictional research, note that diversity citizenship doctrine has been elaborated almost entirely through case law, not statutory text, and historical dictionaries substantially understate the complexity of domicile analysis as it developed in the twentieth century.
The citizen suit entry is a distinct doctrinal area that historical sources do not address at all — this is a creature of mid-twentieth-century administrative and environmental law and must be researched in statutory text, legislative history, and case law, not in the classical dictionaries.
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Historical Dictionary Support
The classical sources agree on the core conception: a citizen is a member of a civil society who possesses its rights and bears its duties. Burrill's gives the most precise formulation — "a member of a commonwealth (civitas,) possessing all the rights which can be enjoyed or exercised under its fundamental laws" — and correctly distinguishes strict citizenship from mere inhabitancy ("every inhabitant is not a citizen"). Black's (both editions) and Bouvier's define the American citizen functionally, with emphasis on voting rights and eligibility for elective office, which was the salient civil privilege at the time of drafting.
Bouvier's is notable for incorporating the Fourteenth Amendment language — "all persons born or naturalized in the United States" — indicating an edition post-dating 1868. Rapalje & Lawrence adds the useful observation that "the same person may often be a citizen for some purposes and not for others," which foreshadows the modern requirement to identify which sense of citizenship is operative in a given legal context.
The English law definition in Bouvier's and Burrill's — essentially, a freeman or inhabitant of a city with recognized privileges — reflects the municipal meaning that preceded the modern constitutional sense. This usage survived into American practice only vestigially and should not be imported into American legal analysis.
What the historical sources collectively miss: the domicile-based analysis for diversity jurisdiction, any treatment of naturalization procedure as it developed in the twentieth century, and the entire citizen suit doctrine. They also do not grapple with the status of women, Indigenous persons, or residents of territories in ways that reflect current law.
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Jurisdictional Note
Citizenship in the national sense is a matter of federal constitutional and statutory law and is uniform across states. State citizenship for diversity jurisdiction purposes, however, is determined by domicile under federal common law, and the domicile analysis — particularly for persons with multiple residences, recent movers, or persons living abroad — can be fact-intensive and circuit-dependent. Some states use "citizen" in their own constitutional provisions in ways that track state domicile rather than national citizenship status.
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Encyclopedia Cross-Reference
Citizen Suits in Environmental Law — Standing, Notice, and Diligent Prosecution (Law Mind Environmental & Energy Law Encyclopedia)
Environmental Enforcement — Citizen Suits, Penalties, and Criminal Prosecution (Law Mind Administrative Law & Government Encyclopedia)
Campaign Finance Regulation — Contributions, Expenditures, and Citizens United (Law Mind Administrative Law & Government Encyclopedia)
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