The elevation of Robert Francis Cardinal Prevost into Pope Leo XIV means that what the novelist Saul Bellow called “an American, Chicago-born” will serve as the vicar of Christ and 267th bishop of Rome. 

White smoke snaked out of the Sistine Chapel on the second day of the papal conclave that convened after the death of Pope Francis, the 265th successor to St. Peter, who was, tradition has it, created as the first pontiff by Christ himself. Never before has an American led the world’s 1.4 billion Catholics.

“Habemus papam” — Latin for “we have a pope” — was the announcement that preceded the introduction of the first pope to bear the name Leo since Pope Leo XIII reigned between 1878 and 1903. Pope Leo XIV, in his maiden address from a Vatican balcony, called for “a united church, always seeking peace and justice.” He spoke in Italian, the language of the Curia, and Spanish, the mother tongue of his predecessor, but not in his native English.

Pope Leo XIV spent so many years abroad in service to the church that both La Repubblica and the Italian national TV network RAI took to calling him “il meno americano tra gli americani,” meaning the “least American of the Americans.” He served for two decades in Peru, whose citizenship he holds, before being created a cardinal by Francis in 2023. That made him one of the newest princes of the church. At 69, he is downright youthful for a modern pope.

Pope Leo XIV is, in another first for a pontiff, a member — and prior general — of the Order of Saint Augustine, which was created in the 13th century as a community of mendicant friars. His affiliation with the Augustinians echoes Francis’s Jesuit commitments. He was the first member of the Society of Jesus to reign as pope. 

Pope Leo XIV appears to share with his predecessor a commitment to the poor. He told the Vatican news agency last year that “the bishop is not supposed to be a little prince sitting in his kingdom.” Before he was created a cardinal, though, he criticized “sympathy for beliefs and practices that are at odds with the gospel,” as well as the “homosexual lifestyle” and “alternative families comprised of same-sex partners.”

The creation of Pope Leo XIV was cheered by some of his most well-known countrymen. President Trump called his elevation an “honor” for America, and Vice President Vance, a practicing Catholic who sometimes clashed with Francis, wrote on X: “Congratulations to Leo XIV, the first American Pope, on his election!” Mr. Vance, who was among the last people to meet with Francis, prayed at the Vatican during Holy Week.

There could, though, be turbulence ahead between Washington and the Holy See. Before Cardinal Prevost slid the fisherman’s ring on his finger he was a frequent critic of the Trump administration. In February he reposted an article titled, “JD Vance is wrong: Jesus doesn’t ask us to rank our love for others.” In 2017, during Mr. Trump’s first term, he retweeted a message declaring that “the world is watching as we abandon our commitment to American values.” 

Cardinal Prevost’s account also reposted a message in 2020 that conveyed a “broken-hearted, sickened, and outraged” reaction to the killing of George Floyd. About 20 percent of Americans are Catholic, though the church’s future, at least demographically, appears to lie in Asia and Africa, where the ranks of the faithful are swelling. The cardinals, though, elected to create the first American pope, rather than the inaugural African or Asian one. 

Pope Leo XIV holds a doctorate in canon law at the Pontifical University of St. Thomas Aquinas in Rome, and he was also educated at Villanova. He is the 14th pope to take the name Leo, with the first being Leo I, who reigned between 440 and 461 of the common era. He is best known for meeting with Attila the Hun, and dissuading the warrior to turn back from conquering Italy.