Mormon now returns to his story. In this case the contentions are arising again, and the division among the people has become sufficient that many of them chose to leave the land of Zarahemla and move northward. It is unlikely that the disaffected emigrants were faithful Nephite believers. Those are still in the land of Zarahemla, and for the moment, are still in control. Given the obvious conflicts with the outside world that are surfacing internally, the faithful have no motivation to leave, but a rather large incentive to stay. Thus this exodus is of dissenters who are leaving to find a new way to live away from the Nephite rule.
This exodus is different from past attempts for two reasons. The first is that successful departures have previously gone south, as witnessed by the departure of Amalickiah and company. The second important difference is that this group who left for the land northward was allowed to leave.
In Alma 50 we have the story of the people of Morianton who attempted this very northward migration:
Alma 50:29
29 Therefore, Morianton put it into their hearts that they should flee to the land which was northward, which was covered with large bodies of water, and take possession of the land which was northward.
Unlike the current emigration, however, Morianton faced a military interdiction by Teancum who turned them back (Alma 50:33-36). This is a very important difference, particularly since these two events are separated by no more than twenty-one years. In the space of twenty-one years the Nephite government had either lost the ability or the will to stop the northward exodus of dissidents. There would have been no less fear of the possession of the north by dissidents twenty-one years later than there was in the earlier instance, but in this case, the exodus is allowed. We should see this as an escalation of the internal dissent in Nephite society, a dissent that will have disastrous effects before the end of the book of Helaman.
Hauck sees the northward expansion as the result of curiosity about the Jaredite lands resulting from the translation of the twenty-four gold plates of Ether, or the aftermath of the last major Lamanite/Nephite war (F. Richard Hauck. Deciphering the Geography of the Book of Mormon. Deseret Book, 1988, p. 175-6). The translation of the plates occurred much earlier (at the time of Mosiah II) and the contents of the plates was apparently kept from the people – certainly from Mormon’s record – until their inclusion by Moroni. This would be an unlikely cause, though the story of the finding of the plates could itself have sparked some interest. Even in that, however, the description was one of ruin and desolation, and would have been the stuff of curiosity, not emigration.
The effect of the war is closer to the correct impetus, but judging from the attempt of the people of Morianton, it was internal pressure more than external pressure that pushed the people to seek a northward expansion. The wars may have exacerbated the problem, but it is the internal disruption of the Nephite polity that allowed this group to leave when a previous group had been prevented in their departure.