Nephi2 succeeded his father Helaman3 in 39 B.C. as the Nephite chief judge, evidently at a young age. Because of wickedness among the Nephites, he resigned the judgment seat in 30 B.C. and went with his younger brother Lehi to preach the gospel of Jesus Christ among the Lamanites. Although imprisoned and threatened with death, they were preserved by the power of God and converted thousands of Lamanites (Hel. 5).
Nephi returned thereafter to Zarahemla, boldly condemned the corrupt Nephite leaders, miraculously revealed the identity of a murderer, and exercised the power of God to invoke a famine on the Nephites. Although the Nephites repented occasionally, their conversion and the peace that followed did not last. When time was about to expire on the prophecy of Samuel the Lamanite regarding the birth of Christ, Nephi passed the records to his son Nephi3 and left, never to be heard of again (3 Ne. 1:3; 2:9).
Welch, John W. "Longevity of Book of Mormon People and the Age of Man." Journal of the Collegium Aesculapium 3 (1985): 34—42.
Melvin J. Thorne