Ammaron instructs Mormon concerning the sacred records—War commences between the Nephites and the Lamanites—The Three Nephites are taken away—Wickedness, unbelief, sorceries, and witchcraft prevail. About A.D. 321–26.
Read Mormon 1 here: https://www.churchofjesuschrist.org/study/scriptures/bofm/morm/1?lang=eng