In my dissertation, I argue that the following statement in an 1835 letter from Oliver Cowdery to William Phelps was an important step in the development of the Mormons’ theology related to baptisms for the dead:
Do our fathers, who have waded through affliction and adversity, who have been cast out from the society of this world, whose tears have, times without number, watered their furrowed face, while mourning over the corruption of their fellowmen, an inheritance in those mansions? If so, can they without us be made perfect? Will their joy be full till we rest with them? And is their efficacy and virtue sufficient, in the blood of a Savior, who groaned upon Calvary’s summit, to expiate our sins and cleanse us from all unrighteousness?
Yet, I wondered who exactly Cowdery meant by ‘our fathers, who have waded through affliction and adversity,” etc. Early Mormons expressed a lot of concern for ancestors who died before Mormonism (a big reason for the embrace of baptisms for the dead), but Cowdery seemed to have particular people in mind. Val Rust’s Radical Origins: Early Mormon Converts and Their Colonial Ancestors (2004) argues that the early Mormon descended disproportionately from New England radicals who were often cast out and persecuted by other New Englanders but I was curious to what degree the early Mormons were aware of their radical ancestors and of their possible connection to them.
After digging through the Messenger and Advocate recently, it turns out that Cowdery was quite enamored with Roger Williams, making two endorsement of him in the Messenger and Advocate. The first was in response to receiving a letter from a missionary who reported on his activities in Providence, Rhode Island, that Cowdery printed a few months before his letter to Phelps.
On the perusal of this letter, the mind recurs back to the history of the individual who founded the Rhode Island colony-Mr. Roger Williams.-Much has been said of his character, talents and personal worth; but on reviewing a short extract of his memoirs, by Professor Knowls, we were delighted to find two remarkable items, said to be connected with his religious belief: One was, “that the true church and ministry, had been lost in the Romish apostasy, and could be again restored, only by a special Apostle raised up for that purpose.” To escape the force of this though, the Rev.-Professor says that, “the laws of interpretation were at that day, but imperfectly known.” What a pity that Mr. Williams, who is represented as being a man of deep piety, and understanding the original languages, in which the scriptures were written, could not have been favored with some modern Professor to teach him the “laws of interpretation!”
The other item was, after learning the Indian tongue, and laboring faithfully to teach them christianity, that the time for the conversion of Pagans was “postponed until another apostle should be sent with a special commission, and that with the restoration of the ministry, the gift of tongues would be bestowed for the purpose.”
We only add, that our sincere prayer is, that many may be found in that place, entertaining the same belief, and looking forward for the same work of God; for most assuredly these views were correct, and according to divine teaching; and as the elders of this church are called upon from every part of the country, we leave that matter for the Lord to direct by his Holy Spirit.
The second statement came from a letter in 1836 that Cowdery wrote to the Messenger and Advocate while on a trip to see family in Boston.
Thirty miles from this stands the city of Providence. The name of the founder of this place, as well as this little State, is familiar with every man acquainted with the history of New England, as well as the cause of his early leaving the colony of Plymouth, and seeking refuge amid barbarians in a dense, trackless forest-it was because he had religion, and his neighbors had not, except such as deals death to its dissenters and those who absent from their communion. Roger Williams was a man of soul-he chose rather the hardship of a new uncultivated home, rather than sacrifice his rights of conscience; and by his saving himself and family from massacre, by the hands of his persecutors, God thus opened a way, or prepared a place, to which others fled in the time of similar difficulties. This good man saw the fallen state of the church, and the want of authority to administer in the holy priesthood; and after various unsuccessful attempts to convert the nations to christianity, hesitated not to declare, that when they should be converted, God would endow men with the gift of tongues, and thus by his power turn them from darkness to light. This I confess is a great puzzle to the priests of the day-They own that Mr. Williams was a learned man-well acquainted with the original languages; and a good, pious christian, strange to tell, “he did not understand the rules of interpreting the scriptures:” He thought the clause found in the Apocalypse, relative to the Savior’s second coming, meant as the great revelator penned it, while these modern men-revelators say otherwise!
Cowdery then demonstrated a general interest in New England’s history by launching into a lengthy discussion of the Salem witch-hunt, after which he mentioned other New England radicals.
In this place and in Boston, you know, the poor Baptists and Quakers, suffered, also, because their religion was better than their neighbors’, of the good steady habits order. Undoubtedly you have read of their sufferings and are prepared to decide upon the injustice of their persecutors as well as the cause. Though we must not forget, while looking at the imperfections of our fathers, that this was the cradle of liberty-where the first germ of American independence was seen to sprout. The celebrated Gen. Putnam was born in Salem, and in Boston did the pure spirit of patriotism kindle to a blaze.
Cowdery seemed to have been interested in his own family history as well. In a letter that Cowdery wrote for his 1838 disciplinary council, Cowdery declared,
My venerable ancestor was among that little band, who landed on the rocks of Plymouth in 1620 with him he brought those maxims, and a body of those laws which were the result and experience of many centuries, on the basis of which now stands our great and happy Government: and they are so interwooven in my nature, have so long been inculcated into my mind by a liberal and intelligent ancestry, that I am wholly unwilling to exchange them for any thing less liberal, less benevolent, or less free.
Cowdery didn’t say who this ancestor was, and Rust doesn’t spend much time on Cowdery’s ancestors in his book, but Cowdery at least was aware of parts of colonial New England’s religious radicalism, felt a link between one radical in particular (Williams) and Mormonism, and felt a desire to be connected to such fathers. Cowdery’s statement to Phelps thus suggested a theological affinity toward New England radicals as an impetus toward the Mormon practice of baptism for the dead and sealings to ancestors.
 See pages 334-46 of my dissertation.
 Oliver Cowdery, “Letter VII to W. W. Phelps, Esq.,” Messenger and Advocate 1 (July 1835): 156.
 James D. Knowles, Memoir of Roger Williams, the Founder of the State of Rhode-Island (Boston: Lincoln, Edmands, 1834).
 “A Summary,” Messenger and Advocate 1 (April 1835): 103-4.
 Oliver Cowdery, letter, Boston, Mass. Aug 24, 1836, Messenger and Advocate 2 (September 1836): 387-91.
 Far West Record, April 12, 1838, josephsmithpapers.org.