A Dictionary of the Book of Mormon/Nephites
NEPHITES, THE. A people descended from Manasseh, the son of Joseph, named after Nephi, the fourth son of Lehi, who, in connection with the Lamanites, occupied the American continent from about B. C. 590 to A. C. 385, when they were destroyed by the latter race. Originally they were the descendants of Nephi, Sam, Jacob, Joseph, and Zoram, but in later ages the distinction was one of religion and government more than of pedigree; hosts of the two peoples having, at different times, seceded from their own races and fused and intermixed with the other.