Book of Mormon
According to Mormons, it is "another testament of Jesus Christ," written by the ancestors of the native Americans. The Book of Mormon claims that native Americans are descended from Jews, who escaped the destruction of Jerusalem and crossed the sea
Book of Mormon
According to Mormons, it is "another testament of Jesus Christ," written by the ancestors of the native Americans. The Book of Mormon claims that native Americans are descended from Jews, who escaped the destruction of Jerusalem and crossed the sea to populate North and South America. This tome is a saga that spans from approximately 600 BC to AD 421.
The Book of Mormon has 15 books, named for their alleged authors, which are divided into chapter and verses. It is written from the perspective of prophets who handed the book down through the generations. The style is similar to Early Modern English, used for the King James Version of the Bible, and borrows at length from biblical authors such as Isaiah. In fact, the book of 2 Nephi contains large passages quoted verbatim from Isaiah (2 Nephi 11-24, Isaiah 7-14 ). The first English edition required thousands of corrections, including bizarre inconsistencies. 
A likely explanation is that Joseph Smith was the sole author and not the translator of the Book of Mormon.
It is also quite possible that the Book of Mormon was written by multiple authors in the 19th century, possibly including Sidney Rigdon, Oliver Cowdery and Joseph Smith.
According to the church, the Book of Mormon was written approximately 600 BC to AD 421 by the prophets named in the text. They were then compiled and abridged by the prophet Mormon into gold plates from the earlier prophet's records which were engraved on metal plates. His son Moroni added a final chapter and hid the gold plates in a hill Cumorah near what was later called Manchester, New York.  These original plates were supposedly found centuries later by Joseph Smith who was directed to them by Moroni, who appeared as an angel, on September 22, 1823.
Smith claimed the language of the original text was "reformed Egyptian." Joseph described the plates thus: "...each plate was six inches wide and eight inches long and not quite so thick as common tin... The volume was something near six inches in thickness....”  He claims to have taken the plates back to his home in 1827. Smith told his followers and family that he was forbidden to show the plates to anyone, or they would be stricken dead. Joseph probably got the idea for buried metal plates from a story that appeared in a Palmyra paper in 1821, describing the discovery of brass plates found in Canada.  Several witnesses, all members of the church, claimed to have seen the plates.
Smith claimed Moroni instructed him in the use of the Urim and Thummim, seer stones which Smith used to translate the tablets. His translation of the gold plates began in 1829. He allegedly used the Urim and Thummim to translate them, but eyewitnesses claimed that Joseph used his other seer stones, including the ones he used during his money-digging exploits, for translation.  Oliver Cowdry claimed that, during the translation of the plates, the plates wouldn't even be present. Joseph would just look into the Urim and Thummim and dictate, taking frequent breaks and walks down by the river to skip stones (Ch 4, pp 61).
Conveniently, the plates were not shown to non-church members and supposedly returned to the angel Moroni.
The book tells of a group of people escaping Jerusalem before its fall to the Babylonians in 586 BCE. They journey to the Americas by boat. The group split into two tribes, the Nephites and the Lamanites, who often warred with each other. Jesus is said to have returned from heaven after his ascension and visited the tribes in the Americas. He established a peaceful and prosperous society, however this reverted to its original state within a few generations. After records of these events were hidden, the Nephites were destroyed, leaving only the Lamanites (who are now known as the Native Americans).
Book also tells of a group called the Jaredites, who travelled from the Tower of Babel to the Americas around 2500 BCE.
It is likely that Joseph Smith got his ideas for the story of the Book of Mormon from several contemporary sources, including Ethan Smith's book View of the Hebrews.  Ethan Smith's book speculated that Native Americans were descended from Hebrew settlers. The view was popular among scholars at the time. 
The View of the Hebrews also compared copper breast plates found in New England burial mounds with the ephod (part of the ceremonial garb) of Hebrew high priests, including the Urim and Thumim. This may also be what spawned the breastplate and seer stones that constituted the Urim and Thumim which Joseph Smith sometimes used when "translating" the gold plates.
The Holy Spirit tells Nephi to kill Laban in order to recover a tablet with genealogy information, which Nephi proceeds to do. (1 Nephi 4:18) Is this the best an all powerful God can do? Perhaps providing a new copy would have been less murderous?
The Book of Mormon contains many blatant errors. It describes a large society with many large cities in the Americans; no evidence for this has been found. Also, it mentions many uses of advanced technology, such as the use of steel. Animals such as horses are said to have existe