The publication of Mormonism Unvailed is significant in Mormon history as it is considered to be the first anti-Mormon book (Mitton 2004, p. xviii). The book represented the first significant opposition to Mormonism by an author who had actually addressed the contents of the Book of Mormon.
Of the many subjects discussed in the book, two had a significantly lasting impact. The first of these was the publication of a number of affidavits and other statements related to the character of Joseph Smith, Jr. and Martin Harris. The second significant item was the introduction of a popular early authorship theory for the Book of Mormon known as the "Spalding€“Rigdon theory of Book of Mormon authorship." (Wikipedia.com)
This volume includes original illustrations from the book and an interactive table of contents.