The Citizenship Primer

What citizenship is

Citizenship is the legal bond between a person and the United States. It carries rights no other status does — the right to vote in federal elections, to hold a U.S. passport, to run for most public offices, to live in the country without condition — and duties, such as jury service and allegiance. Every debate covered on this site is, at bottom, a debate about who holds that bond and on what terms.

Where it comes from

The constitutional text. The first sentence of the Fourteenth Amendment (1868) is called the Citizenship Clause:

“All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside.”

U.S. Const. amend. XIV, § 1 — the Citizenship Clause

Two phrases do the work. Born or naturalized in the United States sets out the two doors into citizenship. Subject to the jurisdiction thereof is the qualifier — and the center of the modern debate about what it excludes.

The statutes. Congress has also legislated on citizenship since 1790. Today the rules live mainly in the Immigration and Nationality Act: 8 U.S.C. § 1401 lists who is a citizen at birth (including persons born in the United States “and subject to the jurisdiction thereof,” echoing the Amendment), and other sections govern naturalization, citizenship for children born abroad to citizen parents, and loss of citizenship.

How citizenship is acquired

Birth in the United States (jus soli, “right of the soil”) — the rule inherited from English common law and written into the Fourteenth Amendment and § 1401(a).
Birth abroad to U.S.-citizen parents (jus sanguinis, “right of blood”) — purely statutory; Congress sets the conditions, such as a parent’s prior residence in the United States.
Naturalization — the process by which an immigrant becomes a citizen: generally five years as a lawful permanent resident (three if married to a citizen), good moral character, an English and civics test, and the Oath of Allegiance.

The key Supreme Court cases

Dred Scott v. Sandford (1857) held that Black Americans could not be citizens. The Fourteenth Amendment’s Citizenship Clause was written to overrule it.
Elk v. Wilkins (1884) held that a Native American born into a tribe was not born “subject to the jurisdiction” of the United States, because he owed immediate allegiance to his tribe. (Congress later extended citizenship to all Native Americans by statute in 1924.)
United States v. Wong Kim Ark (1898) held that a child born in San Francisco to Chinese parents — noncitizens who were lawfully and permanently domiciled here — was a citizen at birth. It is the foundation of the modern birthright-citizenship rule.
Afroyim v. Rusk (1967) held that the government cannot strip a citizen of citizenship without the citizen’s voluntary relinquishment.
Trump v. Barbara (2026) held that children born in the United States to parents unlawfully or only temporarily present are citizens at birth under the Fourteenth Amendment, rejecting a 2025 executive order that had sought to exclude them. Justice Kavanaugh, concurring only in the judgment, would have decided the case on the citizenship statute alone and noted that Congress “could amend” it or enact new exceptions. NCI argues the majority read the Clause incorrectly — that position is ours, not the Court’s — and the ruling is now the controlling law.

How citizenship is lost

Very rarely. A citizen can renounce citizenship voluntarily. The government can pursue denaturalization of a naturalized citizen only for fraud or illegality in the naturalization itself — and in Maslenjak v. United States (2017) the Supreme Court held a criminal denaturalization requires a lie that actually mattered to the grant. Birthright citizens cannot be stripped of citizenship against their will (Afroyim).

The debates today

Birthright citizenship. Should the children of parents unlawfully or temporarily present receive automatic citizenship? After Trump v. Barbara, the constitutional question is settled against reform unless the Court reconsiders or the Constitution is amended; the live front is congressional legislation amending 8 U.S.C. § 1401. NCI’s position is set out in our position paper.
Citizenship and voting. Federal law reserves federal elections to citizens, but registration rests on attestation rather than proof, and some localities have opened local elections to noncitizens. See Citizenship and the Franchise.
Naturalization standards. What should the civics and English tests require, and how seriously should the Oath’s renunciation of foreign allegiance be taken? See Naturalization Integrity.

Three distinctions keep these debates honest: what the text says, what the courts have held, and what policy currently does. They are not the same thing, and this site labels which is which.