Alma 28:1

And now it came to pass that after the people of Ammon were established in the land of Jershon, and a church also established in the land of Jershon; and the armies of the Nephites were set round about the land of Jershon; yea, in all the borders round about the land of Zarahemla; behold the armies of the Lamanites had followed their brethren into the wilderness.

The people of Ammon were set up in the land of Jershon. A church was also set up in the land of Jershon. The Nephite armies stood around the land of Jershon. They stood around all the borders of the land of Zarahemla. The Lamanite armies had followed their brothers into the wilderness.

After the people of Ammon were settled in Jershon and had set up a church there, the Nephite armies formed a defensive ring around Jershon—and all along the borders of Zarahemla. But the Lamanite armies followed their fellow Lamanites into the wilderness.