Ammon was the leader of a Nephite expedition from Zarahemla, sent to discover the fate of Zeniff and his people who had not been heard from for 75 years, according to the Book of Mormon. Zeniff and his followers left Zarahemla and travelled to Nephi, their ancestral home, which was then in possession of the Lamanites. Ammon himself was not a Nephite by birth, but a descendant of Zarahemla and thus a Mulekite. This may have contributed to his expedition, not knowing the actual route to Nephi.