When Pope Francis lands in New York City on Sept. 24 for a whirlwind 39-hour visit, he will go to Manhattan’s centers of power and to its periphery. His public schedule includes both the United Nations to address the General Assembly and an East Harlem school to meet with immigrant students and day laborers.  This juxtaposition is in keeping not only with the pope’s emphasis on serving those at society’s margins, but also with the history of Roman Catholics in New York City.  A community that began as a persecuted minority in the colonial city grew to make up nearly half of all New Yorkers by the end of the Civil War. As the number of Catholics grew, so did their stature. Faced with nativist anti-Catholic fervor in the 19th century, this multilingual, multinational underclass built its own educational and social welfare institutions, eventually becoming an entrenched part of New York’s secular power structure, populating ranks of its police department and City Hall for generations.  The pope’s visit to New York, part of his first trip to the United States, will be brief, but those in town to catch a glimpse of the pontiff can also take in an overview of Catholic New York in a short afternoon. What follows is a point-by-point tour that goes through Lower Manhattan, from Battery Park to Union Square, with a detour uptown.  This is where Catholic New York was started. The downtown parish, the city’s first, was founded in 1785 after the American Revolution brought Catholics and other minorities their religious freedom. It was also home to New York State’s first free Catholic school, which opened its doors in 1800.  It is dwarfed by its shiny new neighbor, One World Trade Center. But St. Peter’s, built in 1834, is hard to find for another reason. Its templelike facade, with a stone pediment and columns, is so stately that from across the street I almost mistook it for a colonial seat of legislature like Federal Hall on Wall Street. But its interior, with an altar of gilded pilasters and crystal chandeliers and redolent of incense, displayed a subtle, ornate beauty. I arrived on a Wednesday afternoon just as daily Mass was ending; office workers on their breaks darted for the doors, while tourists shuffled out slowly, admiring the stained-glass windows.  Latest news and features on Pope Francis’ visit to Washington, New York and Philadelphia in September, his first visit ever.  At the church’s entrance is a statue of Elizabeth Ann Seton, the first American-born saint and founder of Sisters of Charity, who was baptized there at age 30, after her husband’s death. The conversion of a well-born Episcopal widow to an immigrant religion was scandalous at the time.  To see the elegant part of the city, where Mother Seton lived with her husband and children, walk down Broadway to the Staten Island Ferry. Opposite it, sandwiched between skyscrapers, are two brick structures: the Watson House, a Federal-style house built in 1793 and one of the city’s few remaining Colonial structures; and Our Lady of the Rosary Church, built in 1961 on the site of Mother Seton’s former home.  In Catholicism, a shrine houses a relic of a saint, in plain terms, often a body part. I still recall, with alarming detail, St. Catherine of Siena’s severed, decaying head in Italy, so I steeled myself for what was in store here. Fortunately, with Mother Seton’s body resting in Maryland, the chapel had just a speck of her bone.  When I asked the Rev. Msgr. Leslie J. Ivers about the peculiar tradition of relics, he said: “It’s an incarnational religion. Jesus became a human person, so we attach importance to people, their lives.”  Catholic Worker (St. Joseph House)  Site of Elizabeth Ann Seton’s home  Catholic Worker (St. Joseph House)  Pope Francis will say evening prayer on Sept. 25 at St. Patrick’s Cathedral, the soaring, city-block-wide neo-Gothic church on Fifth Avenue built in 1879. But before the Archdiocese of New York resided there, its seat was at St. Patrick’s Old Cathedral, a graceful 1815 basilica on Mulberry Street in NoLIta. It is under renovation until November, but visitors can go on Sundays when it is open for Mass.  One benefactor who helped fund its construction, was Pierre Toussaint, a slave born in Haiti. His masters, fleeing revolution there in 1797, brought him to New York.  Freed in 1807 by his mistress on her deathbed, Toussaint became a sought-after hairdresser for New York society, including for Alexander Hamilton’s daughters. With his earnings, he bought the liberty of several slaves, including his wife’s, and a home on Franklin Street, where he fostered and educated destitute black orphans and took in yellow fever victims.  One issue on which Toussaint remained silent was abolition — as was the Catholic Church in the United States, though some people condemned slavery.  The wall that surrounds old St. Patrick’s graveyard, where Toussaint was buried before his remains were moved to the crypt below the new St. Patrick’s, represents a time when Catholicism was under attack by nativist groups like the Know-Nothing Party.  The journalist and historian Terry Golway, who wrote “Machine Made: Tammany Hall and the Creation of Modern American Politics,” explained that the church’s outer wall, a bulwark with slits to defend it with muskets, was symbolic of what American Catholicism was at the time.  “It was very defensive,” he said. “For a time, those walls were necessary.”  Into this hostile environment arrived thousands of Irish immigrants fleeing starvation from the potato famine of 1847. They were destitute. But there was strength in their numbers — as Tammany Hall, the corrupt faction of politicians who controlled Manhattan’s Democratic Party for 150 years, discovered. They saw the potential in the Irish vote, and paid handsomely for it.  “Coal in the winter, turkey at Christmas, a job, a nod, a wink — in exchange for these services, the Irish were expected to get out and vote,” Mr. Golway said. “It was a transaction.”  Along the way, Tammany, whose headquarters, built in 1929, now house the New York Film Academy at Union Square, assimilated the Irish, pulling them into the ranks of government.  Just as the Irish were gaining their footing, new waves of Italian immigrants were arriving in New York. In 1889, Pope Leo XII sent St. Frances Xavier Cabrini from Italy to tend to them. In a bit of countryside that is now the Washington Heights neighborhood, Mother Cabrini opened a villa dedicated to helping the immigrant farmers and educating girls.  The site is now the St. Frances Cabrini Shrine, where the saint’s body (with a modeled wax head; the real one is in Rome) lies in a glass coffin on the altar. The gilded marble mural behind it, depicting her life, was recently refurbished. (Nearby are Catholic artworks from centuries before: The Cloisters in Fort Tryon Park in Upper Manhattan contains five cloistered abbeys and approximately 5,000 medieval works of art from Europe.)  To get a sense of immigrant life during Mother Cabrini’s time, head downtown again to the Lower East Side Tenement Museum on the Lower East Side. It tells the story of 97 Orchard Street, where from 1863 to 1935 families of five to 10, largely of German, Irish, Jewish and Italian descent, lived in 325-square-foot, three-room apartments.  On a bright Wednesday afternoon, I was a late joiner to a tour group led by Rebeca Miller, a knowledgeable and enthusiastic guide, who — in true New York fashion — is also an actress, currently in what she called a “lesbian pulp fiction web series.”  Some apartments have been left undisturbed since 1935, dilapidated and slanted, with peeling layers of paint, wallpaper and faux-carpet linoleum floors. Others have been refurbished according to their time periods; china and lace-lined shelves reminded me that these were working-class immigrants. Many were worse off.  Standing in the nearly pitch-black hallway, as our guide reminded us that the building didn’t receive electricity until 1924, I thought of the words of another American Catholic, who came to this area in 1917.  In her autobiography, “The Long Loneliness,” Dorothy Day writes about moving from her family’s middle-class home in Chicago to a boardinghouse on Cherry Street under the Manhattan Bridge. It was her first encounter with the city’s immigrant poor — the masses she intended to serve and the reason for her later conversion to Catholicism.  She wrote: “There is a smell in the walls of such tenements, a damp ooze coming from them in the halls. One’s very clothes smell of it. It is not the smell of life, but the smell of the grave.”  Day’s spirit remains alive at St. Joseph House in the East Village, a place that is part of the Catholic Worker movement, founded by Day with Peter Maurin in 1933. The scruffy bright blue building, which houses men who wouldn’t otherwise have a home, stands apart from the restaurants serving $16 cocktails down the block.  The afternoon I went, I found Day’s granddaughter, Martha Hennessy, there. She said she sent Pope Francis an Italian translation of Day’s autobiography with the hope he would soon canonize her. She thinks he will see their like-mindedness.  “He has used the church for what it should be used for — to care for the people,” she said of Pope Francis. “He’s a pope after the heart of Dorothy.”  St. Peter’s Roman Catholic Church (22 Barclay Street; spcolr.org).  Shrine of St Elizabeth Ann Seton at Our Lady of the Rosary Church (7 State Street; spcolr.org/st-seton-shrine-1).  St. Patrick’s Old Cathedral (263 Mulberry Street; oldcathedral.org).  St. Frances Xavier Cabrini Shrine (701 Fort Washington Avenue; cabrinishrinenyc.org).  Lower East Side Tenement Museum (97 Orchard Street; tenement.org).  St. Joseph House (36 East First Street; 212-254-1640; catholicworker.org). Those interested in volunteering at the house are encouraged to call before.  A version of this article appears in print on September 20, 2015, on page TR1 of the New York edition with the headline: A Tourist’s Guide to Catholic New York. Order Reprints| Today's Paper|Subscribe
For visitors, and even Pope Francis, what to do and where to go to really get to know Catholic New York during the papal visit.