The Nephites seem to have had different relationships with other peoples who lived on the American continents. Where the Lamanites blended with other cultures, it seemed the Nephites stood apart and unique from other cultures in the winding down scenes of their history--conjecture since none of it is in the record as presently constituted.
Lehi's seed is a mixture of the sons and daughters of Lehi and Ishmael and the former servant of Laban, Zoram quite possibly with other ethnicities who lived on the American continents. The Church of Jesus Christ of Latter-day Saints does not take a position on where the party that formed the Nephite and Lamanite nations landed, constituting the reason this article uses the term “American Continents” instead of a singular term. Researchers from Latter-day Saint heritage and others have different ideas of where the civilizations in The Book of Mormon could have occurred. Prevalent folklore in Latter-day Saint culture centers around the Natives of the Americas and the island as descendants of Lehi whether by Lamanite or Nephite blood according.
During Mormon's era, the Nephite and Lamanite division was not a matter of family history so much as politically created ethnicities. Much of the history in Mormon’s record suggests that Laman and Lemuel, the eldest sons of Lehi fathered the Lamanite nation and all people of Lamanite descent come from them. A careful read of the record indicates that Lamanite heritage changed after about 500 years to mean people associating with those against the Nephites. In fact, there are examples in Mormon’s record where Nephites who betrayed the nation boldly affirmed new Lamanite heritage.
When the Lamanites rebelled in 320 A. D., they did not do genetic tests to determine if they were descendants of Laman or Lemuel. This group of people, a mixture of all the seeds, made a conscious decision to separate from the government to form a new nation with separate customs and beliefs. These rebels purposely took the name of Lamanite, which probably meant something semantically different than what it meant 300 years earlier.
This group opposed the Gospel of Jesus Christ so much that they rebelled against it and withheld it from their children! In the final battles, the Lamanites fighting the wars were not former Christians, but the children of former Christians with no cultural ties to Christ.
The Nephites were a mixture of the seeds of Lehi who did not reject the cultural ties to the Church of Jesus Christ but did reject the Church and its teachings in full apostasy. Patriotism was the call for most Nephites. In this new patriotism, religious guarantees existed, because Mormon and Moroni identified as Christians. From the things Moroni and Mormon included in their record, other Christians existed, but only as long as the Nephite government existed to protect them.
The new grievances of the new Lamanites were not the same as from the beginning--that the Nephites robbed their fathers of the rightful governance of the people. Now, their excuse was pure hatred. So bitter came the hatred of these new Lamanites toward the Church of Christ that Moroni wrote, “because of their hatred they put to death every Nephite that will not deny the Christ. And I, Moroni, will not deny the Christ; wherefore, I wander whithersoever I can for the safety of mine own life.” [Moroni 1:23] Two groups of the mixture of the seeds of Lehi warred with each other--cousins fighting.
Genealogical records existed, kept so families could trace their ancestry back to Lehi as Mormon recorded, “I am Mormon, and a pure descendant of Lehi. I have reason to bless my God and my Savior Jesus Christ, that he brought our fathers out of the land of Jerusalem, and that he hath given me and my people so much knowledge unto the salvation of our souls.” 3 Nephi 5:20 Possibly this means Mormon traced his paternal heritage back to Lehi--not necessitating his maternal heritage consist of Lehi, especially since all the sons of Lehi Married the daughters of Ishmael. Mormon’s heritage most logically consisted of a mixture of the seeds of all the peoples of the Nephites and Lamanites with a direct paternal line to Lehi. Since other ancestral groups existed due to the Lord leading other groups to that portion of the Americas, Mormon felt it prudent to point out his genealogy.
Laman, a villain in the record akin to Satan himself, could be his ancestor making him still a descendant of Lehi. Because he is righteous, and how closely associated righteousness is with Nephite heritage, generally, people would assume that Mormon was of Nephi’s family line. Mormon does not indicate that his lineage to Lehi is through Nephi, Sam, Lemuel, Laman (the original four brothers), Jacob, or Joseph in the records available currently. Assumptions come from folklore.