B. H. Roberts cites the Book of Mormon in his October 1924 conference talk.
B. H. Roberts, Conference Report (October 1923), 88–93
THE MESSAGES OF THE BOOK OF MORMON
There is just one other thing, however — nay, perhaps two, that I want to call your attention to. The great outstanding thing in the Book of Mormon is the fact of the visit of the Redeemer to the inhabitants of this western world, and the message of life and salvation that he delivered here; the Church which he brought into existence, the divine authority which he established here in the western world. This is what makes the Book of Mormon of so much importance — it is a new witness for God and Christ and the truth of the gospel. These things being true, makes the advent of the Book of Mormon into the world the greatest literary event of the world since the writing of the Decalogue by the finger of God, and bringing it forth by the great Prophet Moses; or the collection and the publication of the testimony in the New Testament that Jesus is the Christ; that he is the resurrection and the life of men; the greatest event since the recording of the Sermon on the Mount, or the summary of the law by Christ: for the Book of Mormon is supplemental to all this, the necessary part to a consistent whole which manifests the mercy and the justice of God in providing these great things of the gospel for the men of the Western world, as well as to men in the Eastern world.
The other thing referred to is this: The Book of Mormon contains a wonderful message to the great Gentile nation — the United States of America — whose rise and supremacy it predicts. If you go no further back than 1830, when the Book of Mormon was brought to the knowledge of the world, it remains one of the mightiest prophecies that is of record — this prophecy of the rise of a great Gentile nation, upon this land of America. Here and there also we catch glimpses of the fact that the inspired men whom God raised up to found this nation, and whom God also raised up to preserve it by their wise counsels — here and there, I say, we get glimpses of the fact that God has inspired their minds to understand the great principles upon which this nation of ours may maintain its pride of place in this Western world, and in the whole world.
. . .
Such are the two great messages of the Hook of Mormon revealed now some hundred years ago, and they constitute the sublimest message ever delivered to the world, because the witnesses whose words are within the book, testify of the Christ and of the truth of the gospel, of the eternal life of man and his power to become indeed, not only the sons of God, but the glorified sons of God: and also because it gives to us a sublime message for the great Gentile nation of this land, telling them the conditions upon which they may continue to enjoy the favor and blessing of God, and maintain their place and power for good in the world.
God has made his Church — this Church of Jesus Christ of Latterdav Saints — his herald to the world concerning these things. May the Lord make us equal to so great a mission, I pray in the name of Jesus Christ. Amen.