More than 60% of the History of the Church was compiled after the death of Joseph Smith, and several passages were altered from William Clayton’s diaries to make them appear to be the writings of Joseph Smith – an easy sign of plagiarism.
For instance, under the date of 1 May 1843, Clayton recorded this statement concerning the Kinderhook plates in his diary:
“Pres[ident] J.[oseph Smith] has translated a portion and says they contain the history of the person with whom they were found & he was a descendant of Ham…”
William Clayton – 1 May 1843, Journal, as cited in Allen, Trials of Discipleship – The Story of William Clayton, a Mormon (Urbana/Champaign, IL: University of Illinois, 1987), 117.
In the History of the Church this has been stolen to make it appear that Joseph Smith was the author:
“I have translated a portion of them, and find they contain the history of the person with whom they were found. He was a descendant of Ham…”
Joseph Smith, Jr. – 1 May 1843, History of the Church of Jesus Christ of Latter-day Saints – Volume 5 (Salt Lake City, UT: The Church of Jesus Christ of Latter-day Saints, 1909), 372.
See also Tanner, Clayton’s Secret Writings Uncovered (Salt Lake City, UT: UTLM, 1982), Introduction.