The Testimonies of the Witnesses is very strong evidence of the authenticity of the Book of Mormon. Throughout their lives, all eleven witnesses confirmed that they saw what they testified that they saw. Some fell away from the Church due to pride. Some came back. Some never did. No one recanted their testimony that they did what they did and saw what they saw.
The first three witnesses were visited by the angel Moroni, who showed them the Golden Plates. The second eight witnesses actually touched and leafed through the translated the Golden Plates. What a wonderful time it must have been, to witness such a gift from God.