The non-Ether sections of the Book of Mormon begin around 600 BC, when Lehi’s family of devout Jews purportedly lived in Jerusalem.
Mormons claim the book was written on golden plates in Reformed Egyptian; though there has never been evidence of this written language. LDS apologists claim the language was not very common and, therefore, not surprising that New World examples of the script have never been unearthed.
The “caractors” offered by Joseph Smith as samples from the plates have been debunked by scholars for years; including Professor Charles Anthon.
One of the most obvious historical problems with Joseph Smith’s claim is that the Jews were enemies with the Egyptians during this time. Hebrew was the sacred language and the Lord was “Against Egypt” (Jeremiah 46:1-2). It is unlikely that this family would write in any sort of Egyptian format.
King Josiah (born 649 BC) was killed in a battle with Egypt during the summer of 609 BC, and Judah then paid tribute to Egypt (II Chronicles 35-36).
Lehi would have never named Nephi’s younger brother Sam since it is an Egyptian name. Sam is an abbreviation of the name Samuel and as such is an American Jonathanism (or half-name).
Some have speculated Joseph Smith patterned the character of Nephi after his own alter-ego. If this is true, then it’s befitting that his brother might be named Sam, since Joseph Smith’s younger brother was named Samuel.