It's called a "famine church," built by Irish who fled starvation in their homeland to make new lives in Philadelphia.
The history of St. Malachy Parish is carved into its walls and ceilings, evident in the shamrocks on the altar and the tilework based on the Book of Kells.
Now, more than 160 years after its founding, its heart beats strong but its bones need work.
On Sunday, parishioners gathered for the third annual Hibernian Mass and Concert - and the start of a campaign aimed at raising $200,000 for critical maintenance during the next five years.
The Rev. Thomas Kletzel, the pastor, said an architectural study identified serious needs that included repointing the exterior. That means the parish of about 350 member families needs to create opportunities to raise money.
The Hibernian event, initiated by Sister Cecile Reiley, formerly the parish services director, helps increase the collection during the service, but also grows interest and enthusiasm around the future of the church, explained the Rev. John McNamee, pastor emeritus.
"Maybe some of the people who were there today will realize the needs of the parish and be moved to help," he said.
Several hundred worshipers gathered on Sunday, a day of remembrance and forbearance, of prayer, of mournful ballads of lost homes and families - the sort sure to fill the eyes of anyone who wears the green. Music flowed through the church: fiddle, uilleann pipe, flute, and classical guitar.
Dell Campbell and John Collins, of the Philadelphia Emerald Society Pipe Band, led a bagpipe procession into the church, playing the traditional "Let Erin Remember" - special for Collins, whose great-grandparents were members of the church.
St. Malachy's was built by brick and faith, known when it opened in 1852 as "the church in the woods." It stood outside the city boundary in an area of dirt streets. North Philadelphia rose around the church, which sits on 11th Street between Jefferson and Master Streets, just south of Temple University.
What began as an all-Irish, all-white church is today as diverse as the city, home to white, black, and brown. It remains a church of immigrants, now welcoming newcomers from Central and South America, members said, and counting its diversity as a core strength.
"Amen to that," said Yuvia Gonzalez, whose family originally came from Mexico.
Her friend Mercedes Martinez, of Puerto Rican heritage, noted that parishioners come from Philadelphia, New Jersey, and the Pennsylvania suburbs, some of them relative newcomers and others, like her, members for decades.
"My father sat right out there," Martinez said, recalling a long-ago moment with her father in the courtyard, "and told the Sister, 'This is your child.' "
Kathy McGee Burns, grand marshal of the forthcoming St. Patrick's Day Parade, took part in Sunday's service.
Her ancestors went to St. Malachy's Church after arriving from Ireland. Her grandmother, Mary Jo Callahan, was one of seven daughters, all of whom were baptized, educated, married, and buried at the church.
She never knew her grandmother, Burns said. But when she goes to St. Malachy's she feels her presence, as though they're visiting each other.
"There's just a wonderful feeling when you go in there," she said. "It's the Celtic feel, but also the new immigrants. . . . There's an influence of it all in the music."
The famine that ultimately created the church occurred between 1845 and 1852, a time in which a million died and at least a million more fled Ireland.
The potato blight destroyed crops across Europe but hit particularly hard in Ireland, where about one-third of the population depended on potatoes for food and jobs.
Burns' father supported St. Malachy's, and she does the same. That kind of generational interest has helped the parish avoid the fate of other city churches that disappeared amid closures and consolidations.
Parishioner and board member Charley McNulty - his great-great uncle belonged to St. Malachy's - believes the church can raise the money it needs for repairs. It's important to act now, he said, before a big cost grows bigger.
"Fifty thousand a year for four years, that's more doable," he said. "It's a special place to come to, even if you don't have a history."