Soon after meeting the prophet, Oliver Cowdery wrote to his friend David Whitmer about Joseph Smith and the ancient divine records they were translating, and the 24-year-old Whitmer shared these letters with his family. As persecution in Harmony grew, Cowdery made arrangements for Whitmer to bring his two-horse wagon to Harmony and take Smith and Cowdery to the Whitmer residence in Fayette, New York, to finish the work of translation.
To ensure a successful harvest, Whitmer needed to plow and prepare the soil before leaving to fetch Smith and Cowdery from Harmony, but when he went out to the fields he found the work had already been done for him. His sister and her children had witnessed three strangers preparing the soil the day before. Whitmer was thankful for this divine intervention that allowed him to leave days ahead of schedule.
Even though Whitmer had not specified the day of his arrival in Harmony, Smith had seen Whitmer's journey in a vision, and he and Cowdery went out to meet him as he approached the town. These miraculous occurrences confirmed Smith's standing as a prophet in the eyes of Whitmer, and the three men quickly became friends.
They packed up Whitmer's wagon for the three-day journey to Fayette. To avoid dangers while traveling, the angel Moroni took custody of the gold plates for the duration of the trip. While en route they passed a friendly old man. "Good morning," he said to them, "it is very warm." Smith asked if he would like to journey with them, but he replied "No, I am going to Cumorah," before vanishing. As it turns out, this was the angel Moroni.
The Whitmer family were gracious hosts to the Smiths and Cowdery. David, his father Peter, and his two brothers John, and Peter Jr. were all baptized and became the prophet's dedicated assistants. The burden of hosting was overwhelming for David's mother Mary, but she did not complain. One day while she was milking the cows, Moroni appeared to her and showed her the gold plates, saying, "Here is a witness to strengthen you."
Martin Harris visited Fayette at this time. In a revelation to Smith, Jesus had said that if Harris acknowledged his wrongs and humbled himself sufficiently he could still become one of the three witnesses to the plates spoken of in the writings of Nephi. Jesus had also told Smith that Oliver Cowdery and David Whitmer, if they exercised sincere faith, could be the other two witnesses. Accordingly, the four men went into the woods to pray.
After two unsuccessful attempts and some intense and heartfelt prayer, the angel Moroni appeared to them, holding the gold plates in his hands. He flipped through the pages, showing the engravings and said, "These plates have been revealed and translated by the power of God. The translation of them which you have seen is correct, and I command you to bear record of what you now see and hear."
Not long afterward, eight more men were chosen to witness the gold plates: the prophet's brothers Hyrum and Samuel, and his father Joseph Sr.; David Whitmer's brothers Christian, Jacob, Peter, and John; and their brother-in-law Hiram Page. The witnesses of these men are contained in every published copy of the Book of Mormon, further substantiating its truth according to divine law such that all the people of earth will be without excuse on Judgement Day if the book is rejected.