In 1826, the bishop of the Boston diocese, Jean-Louis Lefebvre de Cheverus, approved the construction of the Ursuline Convent school on a 24-acre property on a hilltop overlooking Boston Harbor. With financing from wealthy Boston families enthusiastic about the prospect of giving their daughters a private education to rival those of affluent boys, a lavish three-story brick house was built on a sprawling estate. But late into the night on Aug. 11, 1834, spurred by rumors that a nun named Elizabeth Harrison was being held at Ursuline against her will, an angry mob of Protestant men laid siege to the school, setting it ablaze with tar barrels. As the school burned to the ground, the nuns and students absconded out a back entrance.

The United States in the 1830s was a time of nativism and deepening anti-Catholic resentment. The country was experiencing a massive influx of Irish immigrants, almost all of whom were Catholic. Protestants in New England and New York became wary, even paranoid, of the threat of the country tipping toward the Roman Catholic Church. Puritanism was one of the driving forces behind the American Revolution just a few decades prior, and Protestants cherished and would aggressively defend its independence from Rome. The idea that “popery” might be seeping into the states, taking a multitude of insidious forms, was a cause for alarm.

Incipient nationalist movements took advantage of this widespread fear, disseminating conspiracy theories suggesting that the Irish were smuggling in a “foreign Catholic menace” that would not only usurp Protestantism but eventually topple American democracy. It was this wave of anti-Catholic bigotry that made something as heinous as the Ursuline school burning possible, as Protestant newspapers and demagogues preyed on people’s suspicions that parochial schools were run by the Vatican. Everyone involved in the convent burning was eventually acquitted of wrongdoing, further underscoring the grip of anti-Catholic sentiment.