Rare among Southern cities for its large Catholic population, Louisville, Ky., is blessed with two magnificent churches with extraordinary pasts. The churches offer beauty and serenity, two qualities in short supply last century when anti-Catholic mobs nearly destroyed them.

Cathedral of the Assumption

The city's historic Cathedral of the Assumption is one of the three oldest U.S. cathedrals still in use. (The other two are in St. Louis and New Orleans.) Built in 1850, the cathedral has exquisite, leaded, stained-glass windows and a soaring 287-foot spire that holds a 24-foot cross.

The church's interior is a Gothic-style delight, distinguished by its ornate columns, pointed arches and a ribbed vaulted ceiling. The 8,000 ceiling stars, placed on a sea of blue, are 24-karat gold leaf. Given its rich past and impressive architecture, the structure invites reflection and hints at the people who built it and preserved it amid many struggles and joys.

During the Civil War, Bishop Martin John Spalding hosted memorial services at the cathedral for both the blue and gray. In the late 19th century, a beloved and eccentric pastor, Father Michael Bouchet (who, incidentally, patented an early version of the adding machine), began a number of innovative programs to aid the city's downtrodden.

During World War II, patriotic priests donated the 100-year-old, wrought-iron fence fronting the church and rectory to a scrap-metal drive. In the 1960s, racial violence exploded near the church. Also during that time, as the Vietnam War raged, a fiery anti-war sermon resulted in a mass walkout from the Mass.

But the cathedral's most compelling historical drama took place in 1855. This was the era that gave rise to the American Party, which was hostile to immigrants and Catholics. Party members often met in secret. Asked about their activities, they replied that they “did not know anything.” For this reason, they came to be called the Know-Nothings.

In Louisville, hostility toward Catholics mounted as thousands of German and Irish immigrants flowed into the city. Protestants grew alarmed when a German newspaper in town urged its readers to retain their language and customs. Anti-Catholicism reached new heights when a papal official toured the United States, prompting fears of a papal plot to undermine U.S. democracy.

On election day, Aug. 6, 1855, the Louisville Journal urged Protestants to “rally to put down an organization of Jesuit bishops, priests and other papists, who aim by secret oaths and horrid perjuries, and midnight plottings, to sap the foundation of all our political edifices — state and national.” Mobs roamed the street assaulting Irish and Germans and burning homes on “Bloody Monday.” Twenty-two people died.

The cathedral was singled out as a target of the Know-Nothings. Convinced that munitions were being stored inside, the mob prepared to storm the church. Bishop Spalding wisely turned over the keys and responsibility for the building to the mayor, who kept the crowd at bay.

Two days after the riots, as tensions still simmered and revenge was being considered, Bishop Spalding counseled restraint. He wrote an open letter to the Daily Louisville Democrat: “I entreat all to cultivate that peace and love which are the characteristics of the religion of Christ. We are to remain on earth but a few years. Let us not add to the necessary ills of life those more awful ones of civil feud and bloody strife.”

The persecution invigorated the faithful. Catholics rallied around their parishes. Mass attendance shot up. Parochial schools were “as full as an egg — thanks to Know-Nothingism,” Bishop Spalding wrote.

St. Martin of Tours Church

The city's St. Martin of Tours Church also is historically and aesthetically remarkable. St. Martin's 400-foot steeple has risen above the Phoenix Hill neighborhood since 1853. With its German-speaking parishioners and priests, the church was an obvious target for the rampaging mobs of Bloody Monday. Rioters broke into the church but destruction was averted when Bishop Spalding pleaded with the mayor to inspect the church and assure the mob that there were no weapons inside.

St. Martin may be one of the most beautiful neighborhood churches in the country. Its richly detailed interior offers colorful, life-size statuary, stunning stained glass windows and a resplendent high altar. It's also striking from outside and, taken as a whole, the church is a superior example of the power of religious art to convey piety and transcendence.

The church's stained-glass windows were made in the 1890s by the Royal Bavarian Art Institute in Munich. Two small, adjacent chapels have stained-glass windows brought from a 16th-century monastery in Germany; the church dedicated one of them to perpetual eucharistic adoration in 1996.

The massive pipe organ dates from 1876. Made by the renowned Detroit firm of Farrand and Votey, the organ originally ran off electric lines that provided power to nearby trolley cars.

It's best-known holdings are the skeletons of St. Magnus and St. Bonosa, martyred by the Romans in the third century. The relics were donated to the parish in 1901 from an Italian monastery that had been seized by the Italian government. The final resting place of Magnus, a Roman centurion, and Bonosa, a Christian woman, is in the reliquaries in the two side altars.

The endearing statues of the Apostles, made of zinc, were sought by the U.S. government during World War I for use in munitions-making, but the pastor refused the government's offer to replace the statues with marble ones.

Scattered about on the church grounds are images of ducks, the symbol of St. Martin. Legend says he hid in a barn to avoid the office of bishop.

The church nearly closed in the late 1970s as the neighborhood decayed and parishioners moved away. But a dynamic pastor has revived the parish, chiefly through music. Sunday liturgies, enlivened with first-class classical and sacred music, have drawn ever-larger crowds. Today, the parish is a magnet for the entire city.

The church was skillfully restored in 1991. The lighting of the steeple was paid for by the former owners of the Courier-Journal, the successor of the notorious Louisville Journal. From the lineage of a newspaper that fanned the flame of hate sprang the light of faith and reconciliation.

Jay Copp is based in Chicago.