B. H. Roberts says the Book of Mormon's "attitude" is not the same as other books promoting Hebrew origins theory for Native Americans.
B. H. Roberts, Letter to Elizabeth Skolfield, March 15, 1932, in Truman G. Madsen and John W. Welch, "Did B. H. Roberts Lose Faith in the Book of Mormon?" FARMS Report (1985), 95
March 15, 1932.
Dear Elizabeth:
I discover that I omitted an item which I intended to enclose in the letter to you yesterday, to call your attention to the fact that while early authorities on Indian antiquities assigned to the Indians a Hebrew origin by claiming they were descendants of the lost tribes, that, of course, you will remember, is not the Book of Mormon attitude. While assigning to them Israelitish origin it nowhere claims that they are the lost tribes, but instead in the main are derived from the tribes of Ephraim and Manasseh with a slight infusion of the tribe of Judah through the advent of the people of Amulek who came from Jerusalem at the destruction of the families<y> of Zedekiah, an account of which you may read in the Book of Mormon. But the Book of Mormon theory is that the Israelitish descent is from the two tribes of Joseph, Ephraim and Manasseh and this infusion from Judah.
Lovingly,
Father
The "Elizabeth" this letter is addressed to is Elizabeth Skolfield, who served as a missionary under Roberts in the Eastern States Mission. Roberts had no biological children named Elizabeth.