Dear 100 Hour Board,
I've frequently been told that Joseph Smith only had a third-grade education and that Emma claimed he couldn't compose a coherent letter. And in the Come Follow Me manual it says that D&C Section 1 was given, in part, as a response to concerns that Joseph's poor grammar, spelling, and vocabulary would embarrass the Church. Yet Joseph Smith–History sometimes drips with erudition. Did someone help him with it? And if so, who?
—A Fellow Hoople
Like you, I have also heard the claim that Joseph only had a third-grade education. Personally, I never used it in proselytizing settings, because I don't know where the number comes from, and I'm leery of equating Joseph's 19th-century education with 21st-century public school grades. There are plenty of sources documenting that the Smith family was too poor to afford public education, and that Joseph was largely schooled at home with a focus on the Bible--that's good enough for me. He says himself that he was "deprived of the benefit of an education" (see below).
Before I go on, I do want to mention something Anathema pointed out in a flagette on this answer. The implication of stating that Joseph Smith had only a 3rd-grade education is that he stopped there, which isn't true. It is true, at the time that the Book of Mormon was produced, that Joseph was uneducated and (effectively) illiterate, but he wasn't ignorant.
Furthermore, Joseph went on to pursue lessons in all sorts of things later in his life, including lessons in Hebrew, Greek, and other languages. In the King Follet sermon, he mentions studying a German translation of the New Testament and notes that it accords better with his revelations than any other translation. We ought to be more careful not to imply that Joseph never attained any level of education--that's bad history. (It's also a really fascinating factor in how the Church came to insist on the King James Version when the Prophet was not satisfied with confining himself to it--but that's a story for another time).
So, about Joseph's level of education. In a 2017 FairMormon conference address, BYU professor Gerrit Dirkmaat fielded a very similar question with a somewhat tongue-in-cheek remark about Joseph's education:
Q: At what point in Joseph’s development did he transition from a 3rd-grade expression to becoming an eloquent orator and a profound thinker and philosopher?
A: That’s a really good question. We often say that Joseph Smith had a 3rd-grade education. I don’t know if he really had that. It’s not like he went to grade school. Joseph is always intelligent. I think anyone who’s a teacher can tell you that you can tell native intelligence inside of one of your students. Just because they don’t know how multiplication tables work, that’s not actually evidence of someone not being intelligent. Once they’re taught them, then they can use them, right? So Joseph, as is stated, only has the ground rules of those things, but he really sets himself to work trying to educate himself. You see this with their early attempt to learn Hebrew, Joseph becomes pretty well read, and by the time he’s in Nauvoo he seems to be reading a great deal, and that is all being soaked up. But if you read a letter from 1833, he writes a letter to the Church in Missouri in 1833 where he’s talking about the good doctor, Philastus Hurlbut, and there’s probably not a grammatically accurate sentence in that letter, and there’s almost no correct spelling. Even “doctor” is spelled wrong. Even Hurlbut is spelt wrong, which I’m fine with. Obviously spelling is a little bit more fluid in the 19th century, sometimes people say, “Oh, it didn’t matter how they spelt things.” That’s not really accurate – they do have a way of spelling things, and it’s a pretty standard way of spelling things. You can see this from newspapers. You don’t pick up a newspaper and it spells Church with an “i”. Honestly that is one of my favorite misspellings of Joseph’s, early on in his life when he’s writing something, a lot of the time he misspells Church with an “i”; he spells it “Chirch”. He also misspells Edward Partridge’s name all the time, leaving the “r” out – instead of writing Partridge he writes Patridge. Joseph’s from Vermont, so my guess is that he has a kind of New England accent – he doesn’t have a Utah accent. So I know that for many of you that’s going to cause you to lose your faith, to think of Joseph saying, “Me and Edward Patridge gonna go to the chirch, maybe catch a Sox game”. I don’t know if that’s how he was talking about it, but Joseph, you can see in his writing that he certainly is becoming more well-read. He certainly is understanding – even his efforts to alter and update the Book of Mormon in 1837, it’s almost purely on the grounds of “I’ve learned that you probably shouldn’t use the word “that” there,” and he’s trying to change it to make it more grammatically accurate. The best change that he makes in the 1830s to the Book of Mormon is he takes out dozens of “and it came to pass”. So as often as you read it, it was actually way more than that. So he certainly becomes more proficient as time goes on, which is something you might expect from someone. Although I would say that still reading a letter from 1838, you would have a very hard time comparing that to the Book of Mormon and saying, “oh, this is the same level of writing”, even when he’s making the effort.
He's got a point. Take a look at what Joseph wrote regarding his childhood history in 1832, only two years after the production of the Book of Mormon (all spelling, deletions, and insertions original):
"I was born in the town of Charon [Sharon] in the of vermont North America on the twenty third day of December AD 1805 of goodly Parents who spared no pains to instructing me in christian religion at the age of about ten years my Father Joseph Smith Siegnior moved to Palmyra Ontario County in the State of New York and being in indigent circumstances were obliged to labour hard for the support of a large Family having nine chilldren and as it required the exertions of all that were able to render any assistance for the support of the Family therefore we were deprived of the bennifit of an education suffice it to say I was mearly instructid in reading
and writing and the ground of Arithmatic which constuted my whole literary acquirements."
This whole thing is one long sentence. Punctuation was not Joseph's strong suit.
Now, in contrast to the elusive "third-grade" label, the quotation from Emma Smith comes directly from an interview she had with her son Joseph Smith III in the context of the Book of Mormon translation process. From her perspective (and, I would note, the overwhelming majority of his contemporaries), it was simply impossible that the man who penned the passage above could have also produced the Book of Mormon on his own:
"Joseph Smith could neither write nor dictate a coherent and well-worded letter, let alone dictate a book like the Book of Mormon. And, though I was an active participant in the scenes that transpired, and was present during the translation of the plates, and had cognizance of things as they transpired, it is marvelous to me, 'a marvel and a wonder,' as much so as to anyone else."
Anyway, with that long educational tangent over, let's go back to answer your original question. Here's what the Church has to say officially about Joseph Smith--History:
Who Wrote Joseph Smith—History?
The account in the Pearl of Great Price was not the first attempt to record the Prophet’s early experiences. In April 1830 he received a revelation from the Lord requiring that a record or history be kept (see D&C 21:1). However, his efforts were hindered by lawsuits, imprisonments, poverty, and mobs. Oliver Cowdery “served as Church Recorder from April 1830 to March 1831 and again from September 1835 to 1837. He wrote a history of the Church covering the period from ‘the time of the finding of the plates up to June 12th, 1831’” (Dean C. Jessee, “The Writing of Joseph Smith’s History,” Brigham Young University Studies, summer 1971, 442). In March 1831, John Whitmer was appointed to “write and keep a regular history, and assist you, my servant Joseph, in transcribing all things which shall be given you” (D&C 47:1). John Whitmer’s brief written history was lost for many years, but is now available. Oliver Cowdery also wrote eight letters about Joseph Smith’s early visions, which were published in the Latter Day Saints’ Messenger and Advocate in 1834–35.
Joseph Smith commenced work on a history between July and November 1832. It began with the words “A History of the life of Joseph Smith Jr., an account of his marvelous experience and of all the mighty acts which he doeth in the name of Jesus Christ the son of the living God of whom he beareth record and also an account of the rise of the church of Christ” (Dean C. Jessee, “The Early Accounts of Joseph Smith’s First Vision,” Brigham Young University Studies, spring 1969, 278).
Various clerks and historians began three more historical accounts between 1834 and 1836. In the difficult years of 1837 and 1838, Joseph Smith and the First Presidency worked on the history of the Church, sometimes taking a grammar lesson before the writing sessions. Finally, in June 1839, the Prophet undertook the work again. Materials from the previous efforts were assimilated into a new history, which eventually was published in the Times and Seasons beginning 1 March 1842. Elder Franklin D. Richards published extracts from that 1842 history in 1851, and they are now called Joseph Smith—History.
Hopefully this helps! If you're interested in knowing more about the Prophet's education throughout his life, I highly recommend this article from BYU's Religious Studies Center.