W. H. Whitsitt claims that Sidney Rigdon traveled to Pennsylvania to give Oliver Cowdery and Joseph Smith additional text to add to the Book of Mormon.
William H. Whitsitt, Sidney Rigdon: The Real Founder of Mormonism, assembled by Byron Marchant (Salt Lake City: Metamorphosis Publishing, 1988), 159-162, 1888
SECTION THE FIFTH: SECOND REDACTION OF THE BOOK OF MORMON
Chapter I. "John the Baptist" in Pennsylvania
In a preceding portion of this work, reference has been given to the fact that Smith sometimes designated Rigdon under the name of "John the Baptist." A description was there presented of the manner in which Rigdon was studious to execute the functions of this office among his brethren of the Disciple sect on the Western Reserve of Ohio. There can be little question that the designation (D. & C. 354) was admirably well fitted to the figure and the labors of Rigdon in the interests of Mormonism, whether under the shades of his Patmos at Bainbridge or in the more public arena of the Mahoning Association.
In the month of May 1829, it became imperatively important that "John the Baptist" should once more show his face in Pennsylvania. It will be brought to mind that the manuscript of the Book of Mormon had been handed over to Mr. Smith on the early morning of the 22nd of September 1827. Two months after that date, the Disciples sect had made an extraordinary advance in its theological teaching and position. On the 18th of November 1827, Mr. Walter Scott had stood up at New Lisbon, Ohio, and introduced the long-lost "ancient gospel" of baptism for the remission of sins. Rigdon would speedily come upon the track of this innovation. Hayden says he "always caught up and proclaimed the last word that fell from the lips of Scott and Campbell" (History of the Disciples, p. 186). The same author likewise reports that "in March 1828, Rigdon visited Scott in Warren" and gained from his own lips a full account of the "ancient gospel." That was a very highly valued discovery; Hayden declares that Rigdon "was transported" by it (History, p. 192). He could not think of permitting a treasure that sat so near his heart to be neglected in the pages of the Book of Mormon; it was above everything desirable that the "ancient gospel" should make its appearance there.
By the terms of a conversation held with Bentley and Campbell in the summer of 1827, it has been already shown that it was a prime article of Rigdon's policy to have the doctrine of the Book of Mormon conform with exact nicety to the tenets which the Disciples were advocating. He wanted it to demonstrate that "the Christian religion had been preached in this country in the first century" (History of the Disciples on the Western Reserve, p. 13).
To execute this policy, and so open a way for the work he was composing, to the hearts and churches of the Disciples it was indispensable that the dogma which meanwhile had become so dear and prominent among them should be clearly proclaimed by it. It would be a disaster to exhibit to them a volume that claimed the sanction of divine origin and authority, which contains no single hint of the admired novelty.
Furthermore, information would naturally reach him by due course of mail that Mr. Cowdery was daily making rapid progress in the work of transcribing; if he wished to accomplish his purpose it behooved him to act on the spur of the moment. Additions and alterations would be inadmissable or at any rate inconvenient after a few weeks had elapsed.
Somewhere near the beginning of the month of May 1829, Rigdon must have set forth from his home at Mentor, Ohio, to perform the journey to Harmony, Pennsylvania. His arrival at Mr. Smith's place, where the work of transcribing the Book of Mormon was then in progress, probably took place several days before the 15th of May. It was on that day that he and Oliver Cowdery undertook the further business of adding an appendix to the Book of Mormon, which contains the outlines of the "ancient gospel" that Rigdon had so recently learned from Scott and was now so eager to have inserted into the new volume. This appendix was assigned to the closing chapters of the Book of Nephi, beginning with the Twenty-seventh Chapter and continuing to the end of the Thirty-third Chapter. The procedure for this addition is described in the Autobiography of Smith:
We still continued the work of translation on a certain day when we went into the woods to pray and inquire of the Lord respecting baptism for the remission of sins as we found mentioned in the translation of the plates. While we were thus employed praying and calling upon the Lord, a messenger from heaven descended in a cloud of light and laying his hands upon us, he ordained us, saying unto us, 'Upon you my fellow servants, in the name of Messiah, I confer the Priesthood of Aaron, which holds the keys of the ministering of angels and of the Gospel of repentance and of baptism by immersion for the remission of sins; and this shall never be taken again from the earth until the sons of Levi do offer again an offering unto the Lord in righteousness'".
He said this Aaronic Priesthood had not the power of laying on of hands for the gift of the Holy Ghost, but that this should be conferred on us hereafter; and he commanded us to go and be baptized and gave us directions that I should baptize Oliver Cowdery, and afterwards that he should baptize me.
Accordingly, we went and were baptized -- I baptized him first, and afterwards he baptized me; after which I laid my hands upon his head and ordained him to the Aaronic Priesthood, and afterwards he laid his hands on me and ordained me to the same Priesthood, for so we were commanded.
The messenger who visited us on this occasion and conferred this priesthood upon us said his name was John, the same that is called John the Baptist in the New Testament, and that he acted under the direction of Peter, James, and John, who hold the Priesthood of Melchisedek, which Priesthood he said should in due time be conferred on us, and that I should be called the first elder, and he the second. It was on the 15th day of May 1829 that we were baptized and ordained under the hand of the messenger.
If the memory of Mr. Smith had retained all the facts and incidents which transpired prior to the year 1838 when he was here engaged in setting forth and embellishing the course of his early history, he would have suppressed the name of this Messenger. The designation of 'John the Baptist' points so clearly to Mr. Rigdon that it is sufficient to reveal far more than it was desirable should be made known. It was never the fashion of Joseph to take the public thus unreservedly into his confidence. The present instance was indisputably an oversight; the briefest reference to the Book of Doctrine and Covenants, Sec. 35, would have availed to prevent that kind of blunder.
Indeed, this latter passage was itself an oversight; for example, at D. & C. 27:8, under date of August and September 1830, Smith says: 'Which John I have sent unto you, my servants, Joseph Smith, Jun., and Oliver Cowdery, to ordain you unto the first priesthood which you have received, that you might be called and ordained even as Aaron.' It was certainly stupid enough that in December of that same year he should issue another revelation in the course of which he plumply reveals the secret who this 'John the Baptist' was: 'Behold, I have looked upon thee and thy works. I say unto thee, Sidney, thou art blessed, for thou shalt do great things. Behold, thou wast sent forth, even as John, to prepare the way before me.' (D. & C. 35:3-4).
The notion of conferring the Aaronic Priesthood upon Mr. Smith was the result of literalizing a deduction which Rigdon had perversely excogitated from the first four verses of the third chapter of the prophecy of Malachi, where the coming of the messenger who should prepare the way for Christ is foretold. In the fourth verse, it is said: 'Then shall the offering of Judah and Jerusalem be pleasant unto the Lord as in the days of old and as in former days.' Sidney's activity in the character of that messenger could never occur until the Aaronic Priesthood was reinstated; it was clear to the dullest comprehension that 'the offering of Judah and Jerusalem would never be pleasant unto the Lord as in the days of old; unless the sons of Levi should be brought forward to present it.' This conceit was esteemed by that 'diligent student of the Scriptures' as a very brilliant specimen of exegesis, and it is likely that he had already proclaimed this discovery in many Disciple conventicles on the Western Reserve.
Apart from the identity of 'John the Baptist,' which Sidney made sufficiently apparent by the new conceit for the sake of which Smith and Cowdery went into the woods to pray and inquire of the Lord on the 15th day of May 1829, it is not known whether Rigdon had any trouble regarding the introduction of immersion as the exclusive act of baptism. The rite of baptism among the Methodists was celebrated either by affusion or immersion, and they are still somewhat inclined to favor the Methodist habit of accepting liberty in this regard. Whatever scruples Mr. Smith as a person may have entertained about the matter, they were all quietly surrendered in view of the fact that it would be impossible for a leader among the Disciples to lend his hand to promote any religious organization which was not strict to exclude sprinkling and pouring as forms of administering baptism.
Neither does Joseph appear to have laid down any objections to the appellation of 'Elder' with which in the above transaction he was honored. That was a very strict custom on the Disciples, and though numbers of their leaders are now apparently becoming a trifle ashamed of it, in the early days they were absurdly proud of the title as a feature of the 'ancient order of things.' As Mr. Smith was raised to the dignity of 'first elder,' in the new communion it would not be difficult for him to content himself with this rather old-style nomenclature of Rigdon's; henceforth all the preaching force of the Mormons of whatever grade from the Prophet downwards were addressed by the name of 'Elder'.