4 Nephi is one of the shortest books in the Book of Mormon by page count and one of the longest by the span of time it covers, compressing close to two hundred years of Nephite and Lamanite history into a single chapter. It opens directly after Christ's ministry described in 3 Nephi and describes a society transformed by that visit: the text states that there was no contention in the land, that the people had all things common among them, and that distinctions between Nephite and Lamanite, and between free and bond, had been set aside entirely.
The book names this period explicitly as one of unmatched happiness, and its opening decades are narrated almost entirely in this idealized register, without individual episodes, named conflicts or detailed events of the kind that fill the books immediately before it. Only as the text moves further from the initial visitation does it begin to name specific developments again, marking the point at which the unity it describes starts to come apart.
The single chapter records almost no named individuals after its opening decades, which stands in deliberate contrast to the crowded cast of Mosiah, Alma and Helaman; the text seems to treat the absence of notable individual episodes as itself the evidence of a genuinely unified and contention-free society during this stretch.