Anti-Catholic nativism framed Catholicism as un-American into the 1900s. [fact]
As the twentieth century approached, an epoch when industrialism and urbanism were leading to social chaos in America, Catholicism was juxtaposed to "American values." The nativist Josiah Strong admonished Americans in his popular book, Our Country (1888), that Rome could not "make 'America Catholic' . . . without bringing into conflict the diametrically opposed principles of Romanism and the Republic, thus forcing all Romanists in the United States to choose between two masters, both of whom they now confess to serve." In 1928, when Al Smith won the Democratic presidential nomination, newspapers and magazines cast him as "Rome's Tattooed Man."
XREF: Connects to the broader history of American nativism and the anti-immigrant sentiment that also targeted other groups in the same era.
Carl W. Ernst, Islamophobia in America_ Th…, loc. 273