The Book of Mormon introduction has statements from witnesses who saw and felt the plates, and never denied the reality or importance of it, all their lives.

• Even though some disassociated with Joseph Smith, they never denied what they saw, and its truth & reality of it being from God.
• Book by Tad R. Callister: "A Case for the Book of Mormon": in detail about the witnesses, etc. Sounds impressive & very good.
• You can know for yourself if the Book of Mormon is true, and if so that God lives and what is His true Church. He makes a specific promise in it. [main entry]
• There are many other witnesses (those who saw and heard, and reported)