One of the hallmarks of a true Lamanite conversion during this decade or more has been that those who had been Lamanites and underwent the change of heart and soul to accept the gospel, also laid down their weapons.
Mormon writes the ending of this story as though the Lamanites gave up all their lands to the Nephites. That was certainly not the case. Even though the event takes place in Lamanite lands, it appears to involve apostate, or perhaps conquered, Nephites. Therefore, what the Lamanites gave up was probably the land of Zarahemla.
This is not the end of a chapter in the 1830 edition.