Plural marriage among Latter-day Saints is a sort of polygamy (more properly called polygyny) formerly practiced by some members of The Church of Jesus Christ of Latter-day Saints during the Church's 19th century founding days and currently practiced by splinter groups.
Its practice among church members substantially subsided after the Church issued a "Manifesto" against the practice in 1890  (http://scriptures.lds.org/od/1). However, a few members continued to practice plural marriage privately with the approval of a few Church leaders until a second proclamation was issued by the Church in the early 1900s. Under that proclamation, those who continued to practice it became subject to excommunication from the Church.
The Church continues to forbid the practice under the penalty of excommunication, and Church leaders have asked that groups who do practice it should not be referred to as "Mormons" or "Mormon fundamentalists." (Application of the term Mormon is itself controversial for some.)
In the process of re-translating the Bible, Joseph Smith, Jr., the founder of the Church, prayed about the polygynous practices of biblical figures such as Abraham, Isaac and Jacob. He claimed to have received a revelation from God regarding plural marriage (see Doctrine and Covenants 132 (http://scriptures.lds.org/dc/132)), and a new commandment from God to take more wives. According to some accounts Smith was reluctant to practice polygyny, and did so only because an angel appeared with a drawn sword and told Smith that he would "slay" him if he continued to disobey the Lord's commandment. In 1842, at Nauvoo, a small pamphlet named The Peace Maker with Joseph Smith as printer expounded Bible verses in support of polygyny. This pamphlet was not well accepted, and Joseph spoke against it, but many believe its real purpose was to open the way for church acceptance of polygyny.
The practice of polygyny
Polygyny was practiced as early as 1833 although the practice was not publicly taught until 1852, some five years after the Mormons came to Utah, and eight years after Smith's death. Smith introduced the doctrine to select individuals, some of whom (such as Brigham Young) were told to take more wives. Some Mormon leaders at the time voiced their objection to the practice and left the Church. Others struggled with their consciences and agreed to the practice only after much prayer. Brigham Young famously said that after the doctrine was communicated to him, he would gladly have traded places with the body in a hearse he saw passing down the street, than embrace this new doctrine. In one instance the first mayor of Nauvoo, John C. Bennett, was excommunicated for the adulterous practice of "spiritual wifery."
Some of those who left or were driven from the Church set out to expose Smith and his alleged corruption. Eventually this antagonism led to Joseph surrendering himself to jail for charges of riot and treason. While imprisoned, a mob rushed the jail and murdered Smith.
Census studies of various Utah counties show that the percentage of the community practicing plural marriage in 1880 varied from community to community: for example, only 5 percent in South Weber, but 67 percent in Orderville. Studies suggest that the majority of Utah polygamists in the 19th century only had two wives, the man often being a local church leader and the second wife typically being significantly younger.
Joseph Smith's wives
Although there is some disagreement as to the precise figure, many estimates state that Joseph Smith was married to about 33 wives during his life. Under the doctrine of plural marriage, the first wife's consent should be sought before a man marry another wife. A revelation given to Joseph Smith says, "then shall she believe and administer unto him, or she shall be destroyed...and she then becomes the transgressor; and he is exempt" from having her permission (Doctrine and Covenants 132:64-65). Smith's first wife, Emma Hale Smith, was publicly opposed to the practice and Joseph may have married some women without Emma knowing beforehand.
Some of Joseph's wives were older women and some of them young, the youngest being Helen Mar Kimball who was 14. Now, usually viewed as unacceptable in current western culture and illegal in most United States jurisdictions, girls often wed at the age of 14 in the 20th century. Although no evidence exists that Smith had or did not have sexual relations with Helen Mar, it is a practice of some modern Polygamist groups to defer sexual relations when the girl is so young. Accounts of the marriage strongly suggest that one of the primary reasons for this marriage was to join the Smith and Kimball families into the eternities through the sealing of marriage. Initially believing the marriage applied to eternity and not this life, Helen Mar stated she was surprised that she was not allowed by family to attend a youth dance. If there had been sexual relations at that point in the marriage, it seems unlikely she would have had this confusion. Heber C. Kimball, Helen Mar's father, was a devout Church member, Church leader, and close friend of Smith. Heber C. Kimball later married thirty-nine wives.
Polyandry, sexual relations and fathering children
About eleven of Smith's wives were also married to other men (usually other Mormon men in good standing and in a few cases acted as a witness in Smith's marriage to his wife) at the time they married Smith. Typically these women continued to live with their first husband, not Smith. Some accounts point to evidence that Joseph may have had sexual relations with some of his other wives and one wife later in her life stated that he fathered at least one child by one or two of them.
According to sympathizers, Smith, Young and other prominent Church leaders were reluctant to embrace the practice of plural marriage especially given their strict Victorian morals. Some critics contend that Smith at first committed adultery with Fanny Alger, a young maid in the Smith household, and later invented the doctrine of plural marriage to legitimize his immorality.
Some critics argue the LDS Church's current policy against the practice of plural marriage is disingenuous, for several reasons: Plural marriage is still a seminal doctrine to Mormons even if it is not practiced, accepted or discussed at Church meetings (Church leaders are discouraged from teaching or discussing polygamy); and in the case of death, and sometimes in cases of civil divorce or excommunication, men may be sealed in LDS temples to more than one woman simultaneously, while women cannot be "sealed" to more than one man—devout LDSs consider such sealings as eternal, outlasting mortal life and civil marriages. Except under unusual circumstances, men cannot be "sealed" to a second wife while the first is still living. Typically a "cancellation of sealing" (unofficially, but commonly called a "temple divorce") must be granted from the First Presidency of the Church. It is unclear what the presumed status of widowers who are re-sealed is after death, if it is not an effective plural marriage.
- The Wives of Joseph Smith web site (http://www.wivesofjosephsmith.org)
- Richard S. Van Wagoner; Mormon Polygamy: A History; Signature Books; ISBN 0941214796 (Paperback, 2nd edition, 1992)
- Jessie L. Embry; Mormon Polygamous Families: Life in the Principle; University of Utah Press; ISBN 0874802776 (Hardcover 1987)
- Todd Compton; In Sacred Loneliness: The Plural Wives of Joseph Smith; Signature Books; ISBN 156085085X (Hardcover, 1997)
- Anne Eliza Young; Wife No. 19 (1876); Ayer Co Publishing ISBN 0405044887 (Hardcover, 1978); Kessinger Publishing, LLC ISBN 0766140482 (Paperback, 2003)