Definition
A naturalized citizen is a person who was born an alien — a non-citizen of the country in question — and has subsequently acquired citizenship through a formal legal process established by that country's laws. The term distinguishes this class of citizen from a natural-born citizen, who acquires citizenship by birth, either by place of birth (jus soli) or by descent from citizen parents (jus sanguinis).
In the United States context, naturalization is the constitutionally grounded process by which a foreign national satisfies statutory requirements — including a period of lawful permanent residence, demonstrated knowledge of civics and English, good moral character, and an oath of allegiance — and is thereby admitted to full citizenship. Once naturalized, the individual holds citizenship rights equivalent to those of natural-born citizens in nearly all respects. The principal constitutional distinction is eligibility for the presidency and vice presidency, which the Constitution reserves for natural-born citizens.
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Common Language
Modern common usage (Wiktionary): A person who has become a citizen of a country through naturalization, rather than by birth.
Historical common usage (Webster's 1913): One who has been naturalized; a person born in a foreign country but who has been made a citizen by legal proceedings.
The common and legal uses of this term align closely, and the ordinary speaker's understanding is not materially wrong. The gap that matters for legal research is not in the definition itself but in the legal consequences: common usage treats naturalized and native-born citizens as interchangeable, while constitutional and statutory law preserves specific distinctions — most notably the presidential eligibility bar and, historically, the rules governing expatriation and denaturalization — that attach only to naturalized citizens.
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Common Confusion
NATURALIZED CITIZEN vs. LAWFUL PERMANENT RESIDENT (LPR): These are not the same status. A lawful permanent resident holds a green card and may reside and work in the United States indefinitely but has not completed naturalization and does not hold citizenship. Confusion arises because LPR status is typically a prerequisite to naturalization, and the two are sometimes conflated in lay discourse.
NATURALIZED CITIZEN vs. NATURAL-BORN CITIZEN: The terms look similar and are sometimes treated as synonyms in non-legal writing. They are legally distinct. A natural-born citizen acquires citizenship at birth and faces no bar to any elected office. A naturalized citizen acquires citizenship by legal process after birth and is constitutionally ineligible for the presidency and vice presidency. Historical sources sometimes use "native citizen" and "natural-born citizen" interchangeably, which can create confusion when reading older materials.
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Why It Matters in Research
Researchers working with historical legal sources should be alert to several navigational issues.
First, the process and standards for naturalization have changed dramatically over time. Early federal naturalization statutes, beginning with the Naturalization Act of 1790, restricted naturalization to "free white persons." Subsequent legislation progressively extended eligibility, with race-based bars largely eliminated by the Immigration and Nationality Act of 1952. Historical case law on who qualified as a naturalized citizen is therefore deeply tied to racial eligibility questions that no longer control but that saturate pre-1952 sources.
Second, the rights of naturalized citizens in international contexts have a distinct research path. Bouvier's entry flags the question of how naturalized citizens are treated by their country of birth — an issue that animated significant diplomatic controversy in the nineteenth century over whether European powers were bound to recognize American naturalization certificates as overriding claims of continued allegiance. This produced a body of treaty law (the Bancroft Treaties) and consular practice that researchers will not find by searching domestic citizenship doctrine alone.
Third, denaturalization — the revocation of naturalized citizenship — is a legal mechanism that applies only to naturalized citizens and has no equivalent for natural-born citizens. The constitutional limits on denaturalization developed primarily in the twentieth century. Researchers tracing the scope of citizenship rights should follow the naturalized/natural-born distinction carefully, as much of the doctrine on the permanence and security of citizenship arose precisely in challenges brought by naturalized citizens.
Fourth, in state-level historical materials, the term may appear in contexts involving state citizenship distinct from federal citizenship. Pre-Fourteenth Amendment sources sometimes used "citizen" and "naturalized citizen" in ways that conflated state and federal status — a distinction the Fourteenth Amendment clarified by grounding citizenship in birth or naturalization and making federal citizenship primary.
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Historical Dictionary Support
Black's Law Dictionary (both the first and second editions) and Bouvier's converge on the same core definition: a person alien by birth who has received citizenship through the legal processes of the state or nation. The formulations are nearly identical across all three sources, reflecting the settled character of the definitional core by the late nineteenth century.
Bouvier adds the most practically useful gloss: the observation that a naturalized citizen has a right to be treated as such in foreign countries — including, for most purposes, in the country of birth. This international dimension is absent from Black's and reflects Bouvier's broader attention to the law of nations alongside domestic doctrine.
What all three historical sources omit is significant for modern researchers: none addresses the constitutional limits on denaturalization, the statutory requirements for naturalization, the history of race-based eligibility bars, or the Fourteenth Amendment's foundational role in defining citizenship. These are not gaps in the definitions themselves — the term's core meaning is stable — but they mark the boundaries of what historical dictionary entries can supply. For anything beyond the definitional baseline, researchers need primary sources and the encyclopedia entries noted below.
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Jurisdictional Note
Naturalization in the United States is exclusively a federal power under Article I, Section 8 of the Constitution. States may not naturalize citizens independently, though state court proceedings historically administered oaths in naturalization cases. In other federal systems or nation-states, the naturalization process and the rights conferred on naturalized citizens vary considerably, and researchers working in comparative or international law contexts should not assume that the U.S. framework generalizes.
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Encyclopedia Cross-Reference
Naturalization, Citizenship, and Denaturalization Proceedings — The Law Mind Administrative Law & Government Encyclopedia (procedural framework, agency roles, statutory requirements)
Naturalization and Denaturalization — Congressional Power Over Citizenship — The Law Mind Constitutional Law Encyclopedia (constitutional foundations, limits on denaturalization, Fourteenth Amendment citizenship clause)
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