FairMormon is a non-profit organization dedicated to providing well-documented answers to criticisms of LDS doctrine, belief and practice.
Source:William Smith:Jan 1837:a remnant of the branches or seed of Joseph are represented as crossing the sea, and settling this continent of North and South America
William Smith (Jan 1837): "a remnant of the branches or seed of Joseph are represented as crossing the sea, and settling this continent of North and South America"
William Smith in Messenger and Advocate:
Now, the beauty of this simile or figure can only be discovered by those who take the pains to contrast it with the literal fact as it occurred; the relation of which may be found in the book of Mormon, first book of Nephi, where a remnant of the branches or seed of Joseph are represented as crossing the sea, and settling this continent of North and South America. Yes, the concurrence or identity of the prophetic allusion, with the fact as set forth in the book of Mormon, demonstrates the truth of the latter as fully as the works and character of Jesus did the declarations of Moses and the prophets relative to himself. Having now, by unimpeachable bible testimony, and as we believe, sound logical reasoning, followed the remnants of Joseph to their landing upon this continent, our next business must be to inquire whether their history and location, if capable of speaking, would emphatically pronounce them “a multitude of nations in the midst of the earth.” So much of the history of the aborigines of America is known to the world, as would render any attempt to show that they have not been, and are not even still “a multitude of nations,”  perfectly vain and futile. Such was ostensibly the fact at the first settlement of the country by Europeans, and must, according to all human calculations, have existed to a greater extent previous to that time, from the well known coincidence that no social compact, existed among the different tribes, by which their national individuality could be perpetuated; and from a succession of intestine wars to which they were peculiarly addicted, they must have been diminished and commingled with other clans. As to their location, we leave it for the learned to say whether they actually occupy those degrees of latitude which with propriety may be said to comprehend “the midst of the earth.” (italics in original) (emphasis added)
William regards the various Amerindian groups of North and South America as descendants of Joseph.
- William Smith, "Evidences of the Book of Mormon," (January 1837) Latter Day Saints' Messenger and Advocate 3:433-435. off-site