http://josephsmithpapers.org/Journals/9Nov1835.htm
an angel appeared before me, his hands and feet were naked pure and white, and he stood between the floors of the room, clothed <with> in purity inexpressible, he said unto me I am a messenger sent from God, be faithful and keep his commandments in all things, he told me of a sacred record which was written on plates of gold, I saw in the vision the place where they were deposited, he said the Indians, were the literal de<s>cendants of Abraham he explained many things of the prophesies to me, one I will mention which is this in Malachi 4 behold the day of the Lord cometh &c; also that the Urim and Thumim, was hid up with the record, and that God would give me power to translate it, with the assistance of this instrument he then gradually vanished out of my sight, or the vision closed, while meditating on what I had seen, the Angel appeard to me again and related the same things and much more, also the third time bearing the same tidings, and departed; ...
This handwritten account by Joseph Smith dated 1835 seems wholly consistent with what he wrote in the so-called 'Wentworth Letter" of 1842:
On the evening [of] the 21st of September, a.d. 1823, while I was praying unto God and endeavoring to exercise faith in the precious promises of scripture, on a sudden a light like that of day, only of a far purer and more glorious appearance and brightness, burst into the room. Indeed the first sight was as though the house was filled with consuming fire. The appearance produced a shock that affected the whole body. In a moment a personage stood before me, surrounded with a glory yet greater than that with which I was already surrounded. This messenger proclaimed himself to be an angel of God, sent to bring the joyful tidings that the covenant which God made with ancient Israel was at hand to be fulfilled; that the preparatory work for the second coming of the Messiah was speedily to commence; that the time was at hand for the gospel in all its fulness to be preached in power unto all nations, that a people might be prepared for the millennial reign. I was informed that I was chosen to be an instrument in the hands of God to bring about some of His purposes in this glorious dispensation.
I was also informed concerning the aboriginal inhabitants of this country [America] and shown who they were, and from whence they came; a brief sketch of their origin, progress, civilization, laws, governments, of their righteousness and iniquity, and the blessings of God being finally withdrawn from them as a people, was [also] made known unto me; I was also told where were deposited some plates on which were engraven an abridgment of the records of the ancient prophets that had existed on this continent. The angel appeared to me three times the same night and unfolded the same things. After having received many visits from the angels of God, unfolding the majesty and glory of the events that should transpire in the last days, on the morning of the 22nd of September, a.d. 1827, the angel of the Lord delivered the records into my hands.
These records were engraven on plates which had the appearance of gold. Each plate was six inches wide and eight inches long, and not quite so thick as common tin. They were filled with engravings, in Egyptian characters, and bound together in a volume as the leaves of a book, with three rings running through the whole. The volume was something near six inches in thickness, a part of which was sealed. The characters on the unsealed part were small, and beautifully engraved. The whole book exhibited many marks of antiquity in its construction and much skill in the art of engraving. With the records was found a curious instrument, which the ancients called “Urim and Thummim,” which consisted of two transparent stones set in the rims of a bow fastened to a breastplate. Through the medium of the Urim and Thummim I translated the record by the gift and power of God.
In this important and interesting book the history of ancient America is unfolded, from its first settlement by a colony that came from the Tower of Babel at the confusion of languages to the beginning of the fifth century of the Christian era. We are informed by these records that America in ancient times has been inhabited by two distinct races of people. The first were called Jaredites and came directly from the Tower of Babel. The second race came directly from the city of Jerusalem about six hundred years before Christ. They were principally Israelites of the descendants of Joseph. The Jaredites were destroyed about the time that the Israelites came from Jerusalem, who succeeded them in the inheritance of the country. The principal nation of the second race fell in battle towards the close of the fourth century. The remnant are the Indians that now inhabit this country.
I take this from an LDS source at LDS.org; the explanatory gloss of [America] after "this country" is theirs, not mine.
So in the material newly on-line, we have Joseph Smith assuring us in the clearest terms, seven years before the Wentworth letter, that an angel told him three times that 'the Indians were the literal de<s>cendants of Abraham'. And this is a New Englander speaking, to whom 'the Indians' meant the aborigines of North America.
In the light of the new evidence from the Joseph Smith Papers, taken with what we know already from unquestioned sources such as the Wentworth letter, how can one believe in Joseph Smith as a prophet who gave truthful accounts of talks with heavenly messengers, but also deny that the events of the Book of Mormon took place in North America?
Did the angel get it wrong? Did Joseph Smith misunderstand the angel (three times)? Did he give an inaccurate account of what the angel said through forgetfulness or carelessness? All of those possibilities would seem to damage his credibility as a prophet quite seriously, since either his sources were unreliable or he was unreliable as a reporter of what those sources told him.
No doubt there is a good answer to all this.