In May 1839, Prophet Joseph Smith and his followers--driven out of New York, Ohio, and Missouri--established a Mormon settlement on the fever-ridden swamps of Commerce, Illinois. Three years later, the holy city they called Nauvoo had become the largest city in Illinois--about four times the size of Chicago. Nauvoo had its own militia, it's own newspaper, and the members of the Church of the Latter Day Saints were the most powerful voting block in...