Elder Dallin H. Oaks gave the following insight into the Three Witnesses’ powerful testimonies: “The three men chosen as witnesses of the Book of Mormon were Oliver Cowdery, David Whitmer, and Martin Harris. Their written ‘Testimony of Three Witnesses’ has been included in all of the almost 100 million copies of the Book of Mormon the Church has published since 1830. These witnesses solemnly testify that they ‘have seen the plates which contain this record’ and ‘the engravings which are upon the plates.’ They witness that these writings ‘have been translated by the gift and power of God, for his voice hath declared it unto us.’ They testify, ‘We declare with words of soberness, that an angel of God came down from heaven, and he brought and laid before our eyes, that we beheld and saw the plates, and the engravings thereon; and we know that it is by the grace of God the Father, and our Lord Jesus Christ, that we beheld and bear record that these things are true’” (in Conference Report, Apr. 1999, 45; or Ensign, May 1999, 35).
Refer to the chart “The Witnesses of the Book of Mormon Plates” in the appendix (page 409). It lists information about each of the Three Witnesses and the Eight Witnesses.