As the Supreme Court justices prepare to hear a landmark case about birthright citizenship, The New York Times analyzed passenger ship manifests, census and voter records, naturalization petitions and speeches by the justices to learn more about how their families came to America.

The histories of the nine justices who will decide the future of birthright citizenship reflect the broader American experience — one shaped by immigration, migration, and at least one instance of birthright citizenship itself.

The case before them, Trump v. Barbara, challenges an executive order signed by President Donald J. Trump on his first day in office that sought to end birthright citizenship for children born in the United States to parents the administration classified as “undocumented” or “temporarily present.”

The constitutional debate centers on the Fourteenth Amendment's Citizenship Clause, which holds that all persons born in the United States and “subject to the jurisdiction thereof” are citizens. The administration argues this language can be reinterpreted to exclude certain children. Opponents say this violates more than a century of constitutional precedent, including the landmark 1898 Supreme Court decision United States v. Wong Kim Ark.

To understand the personal histories of the justices tasked with ruling on the meaning of American citizenship, The Times examined passenger ship manifests, census records, voter registration lists, and naturalization petitions.

Here is what we found.

Chief Justice John G. Roberts Jr.

Chief Justice John G. Roberts Jr.'s ancestry includes English and Slovakian immigrants who arrived in the United States seeking relief from famine and political instability.

His great-great-grandfather, Richard Glover, was a miner from Atherton, England, who emigrated to the United States in 1863 with his Irish wife, Mary Linskey. His maternal and paternal lines eventually converged in the coal and steel region of Johnstown, Pennsylvania.

The Times investigation found that the family history of Chief Justice Roberts — a member of the Court's conservative wing — includes an example of birthright citizenship: the very right the Court is now being asked to limit.

Justice Clarence Thomas

Justice Clarence Thomas is descended from West African individuals brought to the United States in bondage. Much of his family tree was lost due to the institution of slavery.

Thomas has documented his roots in the Gullah and Geechee cultures of the Georgia and South Carolina low country. He has written extensively about his grandfather, Myers Anderson, who was raised by a formerly enslaved woman and who became the central figure of Thomas's upbringing in Pin Point, Georgia.

He has emphasized the importance of education and self-reliance in overcoming the legacy of slavery — values instilled in him by his grandfather.

Justice Samuel A. Alito Jr.

Justice Samuel A. Alito Jr.'s grandparents emigrated from Italy in 1914. His father, Salvatore Alati, was born in Saline Joniche, Calabria, Italy, and immigrated to the United States as an infant.

Upon arrival, the family's name was “Americanized” from Salvatore Alati to Samuel Alito — a change that reflected the intense pressure immigrants faced to assimilate.

Justice Alito has frequently discussed his parents' struggles with poverty and the pressure to abandon their Italian identity. His father became a teacher and eventually the first director of New Jersey's Office of Legislative Services, a journey from poverty to public service that Justice Alito has described as central to his understanding of America.

Justice Sonia Sotomayor

Justice Sonia Sotomayor's ancestors lived in Puerto Rico during the 1800s while the island was under Spanish colonial rule.

Following Puerto Rico's transition to a United States territory and the passage of the Jones Act of 1917 — which granted U.S. citizenship to those born in Puerto Rico — her parents were part of the mid-20th-century migration wave from Puerto Rico to New York during World War II.

Justice Sotomayor has embraced her identity as a “Nuyorican” — a term for Puerto Ricans raised in New York City. She grew up in the Bronxdale Houses, a public housing project in the Bronx, and has spoken openly about how her mother's emphasis on education propelled her from public housing to Princeton to Yale Law School and ultimately to the nation's highest court.

Justice Elena Kagan

Justice Elena Kagan's family background is rooted in the Jewish immigrant experience. Three of her four grandparents were immigrants from the Russian Empire — from lands that are now part of Ukraine — who arrived in the United States in the early 1900s.

Her mother, Gloria Gettleman, was raised in a Yiddish-speaking household. Justice Kagan has often incorporated cultural and linguistic elements of her Jewish heritage into her work on the bench, and has referenced Yiddish phrases in her judicial writings.

She grew up on the Upper West Side of Manhattan, the daughter of a lawyer and a teacher, and has described her upbringing as deeply influenced by the immigrant values of education, hard work, and civic engagement.

Justice Neil M. Gorsuch

Justice Neil M. Gorsuch is a fourth-generation Coloradan whose ancestral roots in the United States date back several generations on both sides, with origins in England, Germany, and Ireland.

He characterizes his identity largely through his family's history in the American West. His mother, Anne Gorsuch Burford, served as the first female administrator of the Environmental Protection Agency under President Reagan.

Justice Gorsuch has frequently defined his personal identity through his deep connection to Colorado, where he was raised and where he returned to practice law before joining the federal bench.

Justice Brett M. Kavanaugh

Justice Brett M. Kavanaugh's family history is predominantly rooted in Irish ancestry. His paternal great-grandfather, Patrick Kavanaugh, immigrated to the United States from Ireland in the late 19th century.

He possesses strong Irish roots on both sides of his family, with ancestors who settled in Connecticut and New Jersey in the 1800s. He grew up in Bethesda, Maryland, the son of a cosmetics industry lobbyist and a teacher who later became a prosecutor and a judge.

Justice Amy Coney Barrett

Justice Amy Coney Barrett was raised in New Orleans. She has Irish and French ancestry stretching back multiple generations in the United States.

She grew up in Metairie, Louisiana, the eldest of seven children, in a devout Catholic family. Her family's deep roots in Louisiana and the American South span generations.

Justice Ketanji Brown Jackson

Like Justice Thomas, Justice Ketanji Brown Jackson's ancestors were brought to the United States from Africa in bondage.

Her family became United States citizens following the passage of the Fourteenth Amendment in 1868 — the same amendment now at the center of the birthright citizenship case before the Court.

Later generations settled in Georgia, Virginia, and North Carolina. Justice Jackson grew up in Miami, Florida, where her parents — both graduates of historically Black colleges — raised her with an emphasis on public service and education.

Why This Matters

The investigation revealed that the personal histories of the nine justices — immigrant, migrant, enslaved, and native-born — mirror the complex, layered story of how Americans came to be American.

Among these ancestral stories, the Times found at least one instance of birthright citizenship within the family history of the conservative wing of the Court — the very legal principle the justices were being asked to restrict.

The Court heard oral arguments in Trump v. Barbara on April 1, 2026. During arguments, the justices examined historical precedents, including the landmark 1898 decision United States v. Wong Kim Ark, which established the citizenship rights of children born to immigrant parents on American soil.

Several justices appeared skeptical of the administration's argument that the president possesses the unilateral authority to redefine the scope of the Fourteenth Amendment's guarantee of birthright citizenship.

Every American — including those who sit on the highest court in the land — is connected to the immigrant experience. That is what makes this story, and this case, so profoundly American.