Parley P. Pratt describes Kinderhook Plates to John Van Cott, and says they contained genealogy of the Jaredites back to Ham.
Parley P. Pratt, Letter to to John Van Cott, May 7, 1843, MS 5238, Church History Library
We are all in good spirits as a people & rapidly increaseing in numbers I have no further news except that six plates having the appearance of Brass have lately been dug out of a mound by a gentleman in Pike Co. Illinois, they are small and filled with engravings in Egyptian language and contain the genealogy of one of the ancient Jaredites back to Ham the son of Noah his bones were found in the same vase (made of Cement) part of the bones had crumbled to dust & the other part were part preserved the bones were 15 ft. under ground. The gentlemen who found them were unconnected with this church but have brought them to Joseph Smith for examination & translation a large number of Citizens here have seen them and compared the characters with those on the Egyptian papyrus which is now in this city.