In the late 19th century, anti-vice societies that attempted to eradicate obscenity, gambling, and other vices, were founded, led, and supported by the upper classes of Boston and New York but received virtually no support from the upper class of Philadelphia. The literature on moral reform movements argues that such movements are instances of either cultural or status defense unrelated to class conflict, or that they defend strictly material class interests. I argue that the importance of culture in the reproduction of class positions implies that moral reform movements are a form of class politics. Variation in strength of support for the anti-vice movements is explained as a response to the political and social threat posed by the immigrant working class and mediated by cultural consensus within the upper class. -Author