Alma Ch27

The Anti-Nephi-Lehies are led by Ammon to safety into the lands of the Nephites who accept them and let them settle in a land called Jershon where they become called the people of Ammon.
After the Lamanites failed to take their anger out on the Nephites, they come back to the land of Nephi and start to become angry with the Anti-Nephi-Lehies again and start to slay them because they still refuse to fight (v1-3). Ammon and his brethren who loved this people and were loved by them spoke with the king to convince him to flee to Zarahemla, but the king was hesitant and would only agree if the Lord commanded, and even then planned to offer themselves up as slaves to the Nephites to atone for their previous murderings (v4-8). Ammon knew that this would be against the laws of the Nephites so he asked the Lord, and was answered with a resounding yes because things aren't going to get better (v9-12).
So they have their orders and they gather their belongings and leave for Zarahemla but stay in the wilderness for a while to let Ammon and his brethren make sure it would be okay which is actually when they run into Alma and start telling all these mission stories (v13-16). Ammon is so joyful that it takes his strength and he faints, but he is the only one of the group who does, so they travel to the chief judge to share what has happened and ask if the Anti-Nephi-Lehies may live in the land (v17-21). The people basically vote in favor of housing them and give them the land called Jershon near Bountiful, and promise to protect them from their enemies because they swore peace if they help support the armies that protect them (v22-24).
Alma goes with Ammon to where the people were and bares his testimony of his conversion before telling them the good news and left to settle in Jershon and be called the people of Ammon (v25-26). They were particularly known for their perfect honesty, firm faith, adhorrence towards sin, and zeal towards God (v27-28). They would rather suffer death than take another life and because of all this, they were highly favored of the Lord (v29-30).