"It incarnates every unclean beast of lust, guile, falsehood, murder, despotism and spiritual wickedness." So wrote a prominent Southern Baptist official in 1899 of Mormonism. Rather than the "quintessential American religion," as it has been dubbed by contemporary scholars, in the late nineteenth century Mormonism was America's most vilified homegrown faith. A vast national campaign featuring politicians, church leaders, social reformers, the press,...