Jeremiah Cooper reports hearing Martin Harris bear testimony of the BOM.
Jeremiah Cooper, Letter to Ebenezer Robinson, September 3, 1845, rep. Messenger and Advocate of the Church of Christ 1, no. 20 (September 1, 1845): 319
Pittsburgh, September 3, 1845.
Dear Brother in the Lord:
I wish to give you some information concerning the mission that was assigned Elder Brothers and myself at the April Conference. . . . We continued on our journey to Cleveland, Ohio. On this rout we met with many things of interest; we saw Mr. Martin Harris, he bore testimony to the Book of Mormon, said he wrote part of it while Mr. Joseph Smith translated it from the plate of Gold. I have not space in my letter, at this time, to enter into particulars with regard to the conversation we had with Mr. Harris.