Did the general location and borders of the original lands according to Alma 22:27-34 (Nephi, Zarahemla, Bountiful, Desolation) still remain the same or did they lose their significance once the people "were in one"? If political boundaries did disappear, did the peoples that inhabited those lands still basically keep their own culture? I think we will see that they did.
According to John Tvedtnes, we read in 4 Nephi 1:17 that there were no more "-ites" after the coming of Christ, but that all of the people were united in the kingdom of God. However, this evidently has reference to political factionalism, rather than the abandonment of lineage ties. It should be noted that not long before the coming of Christ, the people had dissolved their political ties and retained tribal allegiances (3 Nephi 7:2-4). There is reason to believe that these tribal units continued to exist after the time of Christ. [John A. Tvedtnes, "Book of Mormon Tribal Affiliation and Military Castes," in Warfare in the Book Of Mormon, pp. 308-309] [See the commentary on 4 Nephi 1:36]
Geographical [Theory Map]: 4 Nephi 1:3-18 No Lamanites Or Nephites -- They Are"in One" (36 A.S.--110 A.S.)
4 Nephi 1:19 Nephi, he that kept this last record . . . died, and his son Amos kept it in his stead (Nephite Record Keepers) [[Illustration]]: Nephite Record Keepers. Adapted from [Church Educational System, Book of Mormon Student Manual: Religion 121 and 122, 1989, p. 155