The sacred historian in these verses makes it certain that the time in which all these things happened is thoroughly understood by the reader; so that, also, he may understand the exact time of future events that will influence and give shape and form to Nephite history. These are dates which to him were important: One hundred years had passed away since the days of Mosiah, or the same: number of years that the Nephite Republic had existed. It was also one hundred years of the Reign of the Judges over the people of Nephi.
“And six hundred and nine years had passed away since Lehi left Jerusalem.” Nine years had passed away from the time that Samuel and other prophets had foretold certain signs that would herald the birth of the Savior, or that Christ should come into the world. “Now the Nephites began to reckon their time from this period when the sign was given, or from the coming of Christ; therefore, nine years had passed away.”
It was twelve years since Nephi, the son of Helaman, departed out of the Land of Zarahemla, and had not been seen since, or his whereabouts noted. (See III Nephi 1:2)
For upwards of a dozen years, the Nephites waxed stronger and stronger in wickedness, and notwithstanding that many inspired men appeared among them, preaching and prophesying and warning the people of things to come, each year more adroitly than in the preceding one, the Nephites sought for that which would please their fancy and satisfy their whims. Unashamed, they looked for the baser things of life; everything human ingenuity could suggest, or evil power achieve.