There are places in New York where history, startlingly, palpably, touches one like the wings of a pigeon brushing the face. Many of these places are houses of worship. This is not surprising, for these churches, synagogues, and temples often enfold and preserve the most precious memories of the metropolis. Strolling into Tompkins Square, one glimpses through the trees one such sacred site, the bright yellow, stucco, and brick-and-brownstone St. Brigid’s Church.

The story of the square and the early Gothic Revival church are inseparably intertwined. Early on, the square became a place for immigrants: arrivals from Germany occupied the south side of the square, but by the 1850s, the predominant ethnic group of the quarter was Irish. They had been driven to cross the Atlantic in boats so filthy and unseaworthy that they were dubbed “coffin ships.” It is impossible to estimate exactly how many emigrated, but the figure most often given is one and a half million, with three out of four going to America.

Throughout the 19th century, the number of Irish soared. Working in the iron and construction trades, they made monuments of stone and steel, among them, the Croton Aqueduct High Bridge and the rail lines leading out of the city northward. And there was another type of employment, at the dockyards which flourished along the East River not far from Tompkins Square. The Irish rapidly took over the docks, becoming the dominant group among what was called “alongshoremen.”

These new Irish Americans needed a church. At first they relied on a temporary chapel on East Fourth Street, but that soon proved inadequate. After some difficulty, due to local property owners’ reluctance to sell land for the construction of a Catholic church, the prominent site on Tompkins Square was obtained and the cornerstone laid by Bishop John Hughes on September 10, 1848. So great was the crowd that some of the partially built walls onto which they climbed to get a better view of the ceremony sank under their weight.

The architect chosen for the new church, Patrick Keely, born in 1816, came from County Tiperrary. Keely emigrated to America at age 25 and in the course of his long life — he died in 1896 — designed some 600 churches, among them St. Francis Xavier on West 16th Street and Holy Cross Cathedral in Boston.

When it came to Tompkins Square, the very name Brigid made it inescapably clear that this was an Irish parish. Revered only less than St. Patrick himself, St. Brigid is wrapped in the mists of legend. It is known that Brigid was born about 450 and that she was compassionate, performed miracles, and founded a nunnery at Kildare, Ireland’s first religious community for women.

The church’s tall twin spires were a political as well as a religious proclamation. For its parishioners came from a land where, under what was known as the Protestant Ascendancy, laws enforced by the English stated that Roman Catholic churches, if allowed at all, had to be inconspicuous. These same laws had banned Catholics from public office and from universities. There had even been periods when saying mass was considered treason. The worst of these penal laws had been abolished only in 1829 with the passage of the Catholic Emancipation Act.

Inside St. Brigid’s, the impressive ribbed wooden ceiling of the nave, which resembles an inverted boat, is said to have been fashioned by the shipbuilders who constituted a significant portion of the congregation. Legend has it that they were the models for the carved faces on the corbels supporting the ceiling.

Over the years, St. Brigid’s was embellished with handsome stations of the cross by the French salon painter, Theophile-Narcisse Chauvel, purchased in Paris in the 1870s; with windows of Bavarian stained glass; with a striking altar of marble and Caen stone, and with a superb organ of 1,500 pipes noted for the sweetness of its tone. These were all offerings from the church’s parishioners. Their names on windows and tablets ring with the lilt of a pipe band on St. Patrick’s Day: Burke, Coyle, Dunn, O’Connor, Connolly, Keenan. By the 1880s, the parish’s communicants were counted in the thousands.

But New York neighborhoods are in an almost constant state of flux, and the next century was not kind to St. Brigid’s. As the numbers of Irish around Tompkins Square declined, attendance at mass shrank.

In 1962, the church’s soaring spires, once its pride, were sheared off, out of concern for structural safety. In 2001, Cardinal Egan closed St. Brigid’s; in 2004 he dissolved the parish. The structure is considered dangerous because of an unsound rear wall, and Cardinal Egan has plans to demolish the building. His representative has said “we have every right to proceed with the demolition.”

Former parishioners; public officials, including the speaker of the City Council, Christine Quinn; Irish-American organizations like the Ancient Order of Hibernians; neighborhood activists led by Carolyn Ratcliffe; architects like Pamela Jerome, and preservation groups spearheaded by the New York Landmarks Conservancy have appealed to the archdiocese and to the courts to save the 159-year-old sanctuary. They argue that saving the church would cost $285,000 and not the $7 million or so that the archdiocese has suggested.

Brigid was famed for the abundance of her miracles. Now this monument of Irish faith and pluck awaits its fate. Its voice is stilled by the removal of its organ, mass no longer is allowed, and its high altar has been hauled away. Its handsome carved ash pews, once filled with seamstresses and longshoremen, have vanished. How ironic that a church built to express the jubilant survival of a faith suppressed in Ireland should, in America, be swept away by the Catholic Church.

Mr. Lowe, a cultural historian, is author of “Art Deco New York” and “Stanford White’s New York.”