You can find this issue online here: http://www.centerplace.org/history/ts/v2n09.htm
You can also see the entire letter here: https://www.lds.org/ensign/2002/07/the-wentworth-letter?lang=eng.
There’s an excellent historical introduction here: http://www.josephsmithpapers.org/paper-summary/church-history-1-march-1842/1#historical-intro
________________________
I have a 40-page chapter on the Wentworth Letter in my upcoming book, The Editors: Joseph, William, and Don Carlos Smith. We’re going to release it at the conference on April 6.
Here’s an excerpt from that chapter:
_____________________
The Wentworth letter is an amazing accomplishment, and not only because of the Articles of Faith. It is a succinct explanation of the history of the Church and Joseph’s own experiences.
_____________________
Where you can’t see the entire letter is in the lesson manual Teachings of the Presidents of the Church: Joseph Smith. The reason: the manual edited the Wentworth letter to omit Joseph’s explanation that the Lamanites are the American Indians living in “this country.”
I discussed the Wentworth letter here, in the context of Orson Pratt’s pamphlet about Church history: http://www.lettervii.com/2016/08/letter-vii-in-histories-volume-1.html
Source: Book of Mormon Wars