Rex C. Reeve Jr., “The Book of Mormon Plates,” in First Nephi, The Doctrinal Foundation, ed. Monte S. Nyman and Charles D. Tate Jr. (Provo, UT: Religious Studies Center, Brigham Young University, 1988), 99–111.
On 22 September 1823, after receiving repeated instruction from the angel Moroni, Joseph Smith went to a large hill convenient to his father’s home.
On the west side of this hill, not far from the top, under a stone of considerable size, lay the plates, deposited in a stone box. . . .
Having removed the earth, I obtained a lever, which I got fixed under the edge of the stone, and with a little exertion raised it up. I looked in, and there indeed did I behold the plates, the Urim and Thummim, and the breastplate, as stated by the messenger. (Joseph Smith-History 1:51–52.)
Four years later Joseph Smith was allowed to take these plates into his possession with a strict charge to preserve them until the messenger should call for them. He translated the plates by the gift and power of God, and then published his translation as the Book of Mormon in March of 1830. After accomplishing that which was required of him, Joseph said, “according to arrangements, the messenger called for [the plates], I delivered them up to him; and he has them in his charge until this day” (Joseph Smith-History 1:60).
By opening that stone box Joseph Smith opened to the world a flood of knowledge that will eventually fill the whole earth. That sacred event brought into reality the plan of the Lord which had been in preparation for many years. Before young Joseph completed his work, the world would have the Book of Mormon, Another Testament of Jesus Christ, which stands unequaled in bringing men, worldwide, to Christ, and also the Doctrine and Covenants, the Pearl of Great Price, and the Joseph Smith Translation of the Bible.
In 1827 when Joseph Smith received the gold plates, he found that much of the record was an abridgment of many other records written by ancient kings and prophets living in the Americas. The plates he held referred to several other sets of plates and records, an understanding of which is necessary to understand the Book of Mormon. The purpose of this paper is to analyze the plates of Mormon translated by Joseph Smith and show how the other Nephite records were used to produce the Book of Mormon.
The plates that Joseph Smith received had been personally made by the hand of Mormon, and were called the plates of Mormon. He said, “And behold, I do make the record on plates which I have made with mine own hands” (3 Nephi 5:11). When Joseph Smith received the plates of Mormon, they contained (1) an abridgment of the large plates of Nephi (of Lehi’s family history); (2) an unabridged set of small plates made by Nephi and his successors; (3) an abridgment of the record of the Jaredites made by Moroni; and (4) the writings of Moroni. There was also a sealed portion that was not translated by Joseph Smith.
About the year A.D. 320, the prophet Ammaron, “being constrained by the Holy Ghost, did hide up the records which were sacred . . . which had been handed down from generation to generation” (4 Nephi 1:48). Mormon said,
And about the time that Ammaron hid up the records unto the Lord, he came unto me, (I being about ten years of age, and I began to be learned somewhat after the manner of the learning of my people) and Ammaron said unto me: I perceive that thou art a sober child, and art quick to observe;
Therefore, when ye are about twenty and four years old I would that ye should remember the things that ye have observed concerning this people; and when ye are of that age go to the land Antum, unto a hill which shall be called Shim; and there have I deposited unto the Lord all the sacred engravings concerning this people.
And behold, ye shall take the plates of Nephi unto yourself, and the remainder shall ye leave in the place where they are; and ye shall engrave on the plates of Nephi all the things that ye have observed concerning this people. (Mormon 1:2–4.)
As a young man, Mormon remembered and followed the instructions of the prophet Ammaron and recorded a complete and detailed record of his people upon the large plates of Nephi. “And behold I had gone according to the word of Ammaron, and taken the plates of Nephi, and did make a record according to the words of Ammaron. And upon the plates of Nephi I did make a full account of all the wickedness and abominations.” (Mormon 2:17–18.)
In addition to engraving his own personal record upon the large plates of Nephi, Mormon, years later, near the end of his life, was instructed to make a smaller record of his people, an abridgment of the larger records. He said,
And it hath become expedient that I, according to the will of God, that the prayers of those who have gone hence, who were the holy ones, should be fulfilled according to their faith, should make a record of these things which have been done-
Yea, a small record of that which hath taken place from the time that Lehi left Jerusalem, even down until the present time.
Therefore I do make my record from the accounts which have been given by those who were before me, until the commencement of my day. (3 Nephi 5:14–16.)
. . . therefore I write a small abridgment, daring not to give a full account of the things which I have seen (Mormon 5:9).
He also included in his record the unabridged small plates of Nephi. His son Moroni completed the record and hid up the plates. These then are what are known as the plates of Mormon and are the ones from which Joseph translated the Book of Mormon.
1. The plates were about 6 x 8 x 6 inches and were skillfully made by the hand of Mormon. 
2. They had the appearance of gold leaves and were not quite as thick as common tin.
3. They were engraved in reformed Egyptian (Mormon 9:32).
4. They contained an abridgment from the large plates of Nephi including an abridgment by Mormon of his own more complete record (3 Nephi 5:10) which he had written on those large plates (Mormon 2:18).
5. They contained even less than a one-hundredth part of the history of the seed of Lehi (Jacob 3:13; Words of Mormon 1:5; Helaman 3:14; 3 Nephi 5:8; 26:6; Ether 15:33).
6. They included the small plates of Nephi unabridged (Words of Mormon 1:1–8).
7. A portion was sealed and was not translated by Joseph Smith (Ether 5:1).
8. These are the plates from which Joseph Smith translated the Book of Mormon by the gift and power of God.
9. The plates were returned to Moroni (Joseph Smith-History 1:60).
In translating the plates of Mormon, Joseph Smith learned that many other records and plates were kept and preserved by the family of Lehi. The history and doctrine from these other records weave in and out of the text of the plates of Mormon and combine together into a harmonious testament of Jesus Christ. Elder Boyd K. Packer said, “As the influence of that message is traced from generation to generation, more than twenty writers record the fate of individuals and of civilizations who accepted or rejected that testament.” 
The first set of other plates Mormon refers to is the plates of brass, which Nephi and his brothers returned to Jerusalem to obtain. Nephi said:
And behold, it is wisdom in God that we should obtain these records, that we may preserve unto our children the language of our fathers;
And also that we may preserve unto them the words which have been spoken by the mouth of all the holy prophets, which have been delivered unto them by the Spirit and power of God, since the world began, even down unto this present time. (1 Nephi 3:19–20.)
The brass plates contained:
The five books of Moses, which gave an account of the creation of the world, and also of Adam and Eve, who were our first parents (1 Nephi 5:11);
And also a record of the Jews from the beginning, even down to the commencement of the reign of Zedekiah, king of Judah (1 Nephi 5:12);
And . . . the words . . . of all the holy prophets, which have been delivered unto them by the Spirit and power of God (1 Nephi 3:20; see also 1 Nephi 5:13);
And . . . a genealogy of [Lehi’s] fathers (1 Nephi 5:14).
The brass plates were comparable to, but more complete than, our current Old Testament down to about 600 B.C. (1 Nephi 13:23). They proved to be of supreme importance to the family of Lehi by preserving their language and spiritual heritage. About 130 B.C. King Benjamin explained to his sons that “were it not for these [brass] plates, which contain these records and these commandments, we must have suffered in ignorance, even at this present time, not knowing the mysteries of God” (Mosiah 1:3).
Alma later explained to his son Helaman that the brass plates “have enlarged the memory of this people, yea, and convinced many of the error of their ways, and brought them to the knowledge of their God unto the salvation of their souls” (Alma 37:8).
Mormon did not abridge the brass plates or include them with his record. He did, however, include quotes from them which support and elucidate many Bible events and doctrines. In addition, the plates of brass may have set the pattern for the Nephite practice of preserving their writings on metal and may have established the language which would be used in other records.
Even though they were armed with the scriptures recorded on the plates of brass, as his family journeyed toward the promised land, Lehi began keeping a record which would eventually become the foundation record for a major part of the Book of Mormon. “He kept something of a secular account of their journeys, interspersed with his revelations and teachings and spiritual experiences. Nephi succeeded his father, Lehi, as keeper of the record, which became known as the large plates of Nephi.” 
It is not clear from the Book of Mormon just when Lehi began keeping his written record. Nephi seems to have started his large plates about 590 B.C., soon after arriving in the promised land. When Nephi started writing, he included the record of his father. Perhaps Lehi began his record soon after he was commanded to leave Jerusalem, but this cannot be affirmed. In the small plates written about twenty years later, Nephi said that he abridged the record of his father (1 Nephi 1:17), but there is no statement concerning when Lehi began his account.
In explaining the record of the large plates, Nephi wrote:
And it came to pass that the Lord commanded me, wherefore I did make plates of ore that I might engraven upon them the record of my people. And upon the plates which I made I did engraven the record of my father, and also our journeyings in the wilderness, and the prophecies of my father; and also many of mine own prophecies have I engraven upon them.
Wherefore, I, Nephi, did make a record upon the other plates [the large plates of Nephi], which gives an account, or which gives a greater account of the wars and contentions and destructions of my people. And this have I done, and commanded my people what they should do after I was gone; and that these plates should be handed down from one generation to another. (1 Nephi 19:1, 4.)
Shortly after Nephi began his small plates, he wrote, “Upon the other plates [the large plates of Nephi] should be engraven an account of the reign of the kings, and the wars and contentions of my people” (1 Nephi 9:4).
The large plates became the official historical record of the people of Nephi. Pursuant to Nephi’s instructions, these plates were enlarged and handed down from generation to generation, thus becoming a large and detailed record. For over four hundred years, down to the reign of King Benjamin, the large plates were mostly historical and kept by the kings (Words of Mormon 1:10) or by those appointed by the kings to record their history.
And I, Jarom, do not write more, for the plates are small. But behold, my brethren, ye can go to the other plates of Nephi [large plates]; for behold, upon them the records of our wars are engraven, according to the writings of the kings, or those which they caused to be written. (Jarom 1:14.)
The large plates were kept by the kings down to the reign of King Benjamin, about 130 B.C. Following this time period, the plates were apparently the responsibility of the prophets (Alma 37:1; 45:2; 50:38; 63:1).
In order to understand clearly the significance of the changes that occur at the time of King Benjamin, we must return to the days of Nephi. About thirty years after leaving Jerusalem and about twenty years after having begun his large record, Nephi was commanded of the Lord to make a second record for a “wise purpose” (1 Nephi 9:5). Nephi clearly recorded his intent in writing yet another record.
And thirty years had passed away from the time we left Jerusalem. And I, Nephi, had kept the records upon my plates, which I had made, of my people thus far [large plates].
And it came to pass that the Lord God said unto me: Make other plates [small plates]; and thou shalt engraven many things upon them which are good in my sight, for the profit of thy people.
Wherefore, I, Nephi, to be obedient to the commandments of the Lord, went and made these plates [small plates] upon which I have engraven these things.
And I engraved that which is pleasing unto God. And if my people are pleased with the things of God they will be pleased with mine engravings which are upon these plates [small plates].
And if my people desire to know the more particular part of the history of my people they must search mine other [large] plates. (2 Nephi 5:28–33.)
And upon these [small plates] I write the things of my soul, and many of the scriptures which are engraven upon the plates of brass. For my soul delighteth in the scriptures, and my heart pondereth them, and writeth them for the learning and profit of my children. (2 Nephi 4:15.)
Jacob, Nephi’s younger brother, further explained the purpose of the small plates:
And he gave me, Jacob, a commandment that I should write upon these [small] plates a few of the things which I considered to be most precious; that I should not touch, save it were lightly, concerning the history of this people. . . .
For he said that the history of his people should be engraven upon his other [large] plates, and that I should preserve these [small] plates and hand them down unto my seed, from generation to generation.
And if there were preaching which was sacred, or revelation which was great, or prophesying, that I should engraven . . . them upon these [small] plates, and touch upon them as much as it were possible, for Christ’s sake, and for the sake of our people. (Jacob 1:2–4.)
It mattereth not to me that I am particular to give a full account of all the things of my father . . . for I desire the room that I may write of the things of God.
For the fulness of mine intent is that I may persuade men to come unto the God of Abraham, and the God of Isaac, and the God of Jacob, and be saved.
Wherefore, I shall give commandment unto my seed, that they shall not occupy these [small] plates with things which are not of worth unto the children of men. (1 Nephi 6:3–4, 6.)
This I do that the more sacred things may be kept for the knowledge of my people. . . . I do not write anything upon plates save it be that I think it be sacred. (1 Nephi 19:5–6.)
I have received a commandment of the Lord that I should make these [small] plates, for the special purpose that there should be an account engraven of the ministry of my people (1 Nephi 9:3).
It appears the large plates of Nephi were kept and expanded by the kings, but the small plates of Nephi were kept by the prophets, and were not expanded. The last writer on the small plates, Amaleki, merely comes to the end of the last plate with the abrupt announcement that “these plates are full. And I make an end of my speaking.” (Omni 1:30.)
Nephi provided a dual set of records, one basically historical and the other predominantly spiritual, kept by kings or by prophets down to the reign of King Benjamin.
The first important change that took place at the time of King Benjamin was that the small plates of Nephi became full, and this separate spiritual record was given to King Benjamin for safekeeping (Omni 1:25). Thereafter the small plates remained, unaltered, among the large plates of Nephi.
A second important change during the time of King Benjamin was that the large plates of Nephi were now used to record both secular and spiritual events. There was no longer a separate spiritual record being kept; therefore preachings, visions, and prophecies, etc., were included in the large plates.
A third important change affecting the record was that beginning with King Benjamin all of the records, including the large plates of Nephi, were kept by righteous men, most of whom were prophets as well as political or military leaders.
The combining of secular and spiritual records in the hands of the prophets produced a more balanced account. It was from this portion of the record that Mormon was able to abridge a major part of the Book of Mormon and include a powerful mixture of historical and spiritual writings.
When Mormon finally received the records the prophet Ammaron had hidden up, he added to the large plates of Nephi an account of his people and the events that occurred during his lifetime (Mormon 2:18). He later abridged this complete record for the final latter-day account (Mormon 5:9). In a final effort to preserve the records and the sacred treasures of his people, Mormon hid them all up in the hill Cumorah and gave only a few of the plates to his son Moroni.
I, Mormon, began to be old; and knowing it to the last struggle of my people, and having been commanded of the Lord that I should not suffer the records which had been handed down by our fathers, which were sacred, to fall into the hands of the Lamanites, (for the Lamanites would destroy them) therefore I made this record out of the plates of Nephi, and hid up in the hill Cumorah all the records which had been entrusted to me by the hand of the Lord, save it were these few plates which I gave unto my son Moroni (Mormon 6:6).
Near the end of his life, Mormon wrote a letter to his son Moroni. “I trust that I may see thee soon; for I have sacred records that I would deliver up unto thee” (Moroni 9:24). Mormon’s desire was granted. He was able to preserve all the sacred records of his people and give “these few plates” unto Moroni (Mormon 6:6).
From the record and from his original response, it seems that the plates of Mormon which Moroni received were small and almost full. Moroni, writing soon after the final destruction of his people in A.D. 385, said,
Behold I, Moroni, do finish the record of my father, Mormon. Behold, I have but few things to write, which things I have been commanded by my father.
And my father also was killed by them, and I even remain alone to write the sad tale of the destruction of my people. But behold, they are gone, and I fulfil the commandment of my father. And whether they will slay me, I know not.
Behold, my father hath made this record, and he hath written the intent thereof. And behold, I would write it also if I had room upon the plates, but I have not; and ore I have none, for I am alone. My father hath been slain in battle, and all my kinsfolk, and I have not friends nor whither to go; and how long the Lord will suffer that I may live I know not. (Mormon 8:1, 3, 5.)
About fifteen years later, in A.D. 400, Moroni returned to the record and added eight verses and closed by saying,
And whoso receiveth this record, and shall not condemn it because of the imperfections which are in it, the same shall know of greater things than these. Behold, I am Moroni; and were it possible, I would make all things known unto you.
Behold, I make an end of speaking concerning this people. I am the son of Mormon, and my father was a descendant of Nephi. (Mormon 8:12–13.)
Even after fifteen years, it seems that Moroni was still without additional plates as his comments are brief as he bids farewell.
The third time Moroni came back to the records something had changed. He did not give the new date, but room on the plates no longer seemed to be a problem. Moroni finished the record of his father (Mormon 8 and 9), abridged the twenty-four gold plates of Ether, wrote his own book, wrote part of the title page, and added a large amount which was sealed and not translated by Joseph Smith.
When space was no longer a problem, Moroni abridged the record of the Jaredites, which he took from the twenty-four gold plates found by the people of Limhi in the days of King Mosiah. He started his abridgment by saying,
And now I, Moroni, proceed to give an account of those ancient inhabitants who were destroyed by the hand of the Lord upon the face of this north country.
And I take mine account from the twenty and four plates which were found by the people of Limhi, which is called the Book of Ether. (Ether 1:1–2.)
The Jaredites were a separate people from the family of Lehi. They came to this land many hundreds of years before Lehi, at the time the languages were confounded at the Tower of Babel. Their records were translated with the help of “interpreters” prepared by the Lord for that very purpose.
Ether was the last prophet of the Jaredites. He was rejected, and hid himself in caves, and recorded the complete destruction of his people (Ether 13:13–14).
Moroni wrote in great detail the visions and teachings of the brother of Jared. He said,
Behold, I have written upon these plates [plates of Mormon] the very things which the brother of Jared saw; and there never were greater things made manifest than those which were made manifest unto the brother of Jared.
Wherefore the Lord hath commanded me to write them; and I have written them. And he commanded me that I should seal them up. (Ether 4:4–5; see 2 Nephi 27:7.)
Moroni sealed up this portion of his record with instructions to the future translator, “And I have told you the things which I have sealed up; therefore touch them not in order that ye may translate; for that thing is forbidden you, except by and by it shall be wisdom in God” (Ether 5:1).
We do not know exactly how large a portion of the plates of Mormon is sealed. Estimates range from one-third to two-thirds. Joseph Smith simply recorded: “a part of which was sealed.”  Whatever the portion, Moroni’s sealed writings were extensive and very important and will yet be brought forth.
Elder Bruce R. McConkie, commenting on the contents of the sealed plates, said,
When, during the Millennium, the sealed portion of the Book of Mormon is translated, it will give an account of life in the premortal existence; of the creation of all things; of the Fall and the Atonement and the Second Coming; of temple ordinances, in their fulness; of the ministry and mission of translated beings; of life in the spirit world, in both paradise and hell; of the kingdoms of glory to be inhabited by resurrected beings; and many such like things.
As of now, the world is not ready to receive these truths. 
In A.D. 421, Moroni finished his record and buried the plates of Mormon, along with other sacred treasures, where they remained until he personally delivered them to Joseph Smith in 1827.
Through more than nine hundred years, the records and sacred things of the family of Lehi had become very extensive. For generations, the Lord had been preparing the background materials from which he would draw together the most powerful testament of Jesus Christ ever written. The records of prophets, peoples, blessings, destructions, visions, covenants, and promises were now in place. By revelation, the prophet Ammaron hid these valuable records up and charged a ten-year-old boy to remember them and add to them when he became twenty-four years old. Mormon faithfully protected the sacred records and diligently recorded his observations concerning his people.
After a lifetime of obedience and service, Mormon in his old age was prepared, and the time was right for him to compile what would become known as the Book of Mormon, Another Testament of Jesus Christ. The command was given, and Mormon began a labor of love that would bless future generations.
With the publication of the Book of Mormon in March 1830, Joseph Smith made available to the world that portion of the record selected by the Lord to stand as another testament of Jesus Christ. The book contains the promise and the warning that this small record is a test. For those who receive the Book of Mormon and believe it, “then shall the greater things be made manifest unto them.” For those who reject it, “then shall the greater things be withheld from them, unto their condemnation.” (3 Nephi 26:9–10.)