In Trump v. Barbara, the Supreme Court recently reaffirmed a long series of decisions, holding that “[a] child born on American soil and subject to American law [is] an American citizen.” The Supreme Court previously held in the landmark 1898 decision United States v. Wong Kim Ark, that the Citizenship Clause codified the “ancient and fundamental rule of citizenship by birth within the territory, in the allegiance and under the protection of the country.” 

While no Supreme Court case has directly answered the question of whether someone born in a U.S. territory has a right to citizenship, just five years after the Citizenship Clause was ratified, the Court concluded in the Slaughter-House Cases that the Fourteenth Amendment “pu[t] at rest” any notion that “[t]hose … who had been born and resided always in the District of Columbia or in the Territories, though within the United States, were not citizens.”