Helaman’s father, Alma, passes from the earth in the nineteenth year of the reign of the judges, and Helaman follows in the thirty fifth year. We do not know how old Helaman was when he died, only that he survived his father for fifteen to sixteen years. This is not unreasonable for one who might have been born when his father was in his early twenties. What this does mean is that Helaman is fighting wars up to five years before his death, and actively preaching more recently than that.
Textual: Mormon’s chapter ends because the story he has been telling has ended. Mormon’s purpose in including these military battles has demonstrated his theme of preservation through faith on the Lord. What remains is a cleanup chapter that will finish the formal record of the book of Alma.