Simon Legree's taunting invitation to “join [his] church” reminds us that the novel routinely credited with abolishing slavery relied for part of its force on anxieties surrounding religious conversion. Although conversion as the emotional surrender to faith under one or another form of Protestantism remained the norm when Harriet Beecher Stowe was writingUncle Tom's Cabin, as many as 700,000 Americans did join the Roman Catholic Church as converts in the 19th century. The middle third of the century also saw the arrival of nearly 3 million Catholic immigrants, whose perceived intemperance, sexual license, and conspiratorial designs on American institutions animated white Protestant preaching and political action more consistently than did the evils of slavery or racism.