The Vatican conclave surprised the world this week by selecting the first American pope, a native of Chicago. Soon after, a respected genealogist surprised the world by revealing that the new pope’s heritage connected him to far more strands of the American experience than previously known.

Robert Francis Prevost, 69, who took the name Pope Leo XIV, descended from Creole people of color from New Orleans.

The detective work of Jari Honora, the New Orleans genealogist and historian, was based on analysis of historical documents, including census records, many of which are presented here. Other documents were unearthed by the archdiocese of New Orleans or obtained independently by The New York Times.

In their totality, the documents begin to trace the story of a family, on Pope Leo’s mother’s side, with a diverse background rooted in New Orleans’s unique Afro-Caribbean culture that later moved to Chicago in the early 20th century.

It is unclear why they left, but many Creole families like theirs moved north at the time in search of better-paying jobs and a less racially hostile environment — a story that finds parallels in the new pope’s emphasis on tending to migrants and poor people.