1 Nephi 12
It is interesting that Nephi is shown the people as descendants from the fathers that they chose to emulate without regard to the fact that their bloodlines were almost certainly quite intermingled. The Anti-Nephi-Lehis chose to claim their descent from a righteous progenitor (Lehi) rather than their unrighteous progenitor (Laman). In like manner, the people who chose to reject the gospel of Christ took upon them the name of an unrighteous man (Laman – whether he was their actual progenitor or not) and the people of the church became known by the name of his righteous brother (Nephi) when they once again needed a name to distinguish themselves publicly.