In the early 1840’s Joseph Smith learned about polygamy while translating the Book of Mormons. He explained it to Brigham Young, but both were reluctant to institute the principle. By the 1850’s it was instituted, but members of the Mormon Church no longer engage in polygamy.
Many people including members of the Mormon Church wonder why polygamy was practiced. The best answer is because God commanded them. God has not revealed why he instituted polygamy in the early days of the Church, but some people believe that it was done to raise a large number of second and third generation of Church members who were born into families with parents deeply devoted to the Church. This is because men had to be called by God to practice polygamy and their worthiness was strictly watched.
In 1890 the Prophet Wilford Woodruff issued a proclamation that officially stopped the practice of polygamy within the Mormon Church. By this time there were actually very few people who were practicing polygamy. The main reason why polygamy was stopped is because the Mormon Church teaches that its members are subject to the laws of their land, and the United States had passed a law making polygamy illegal. Wilford Woodruff went to the Lord and asked him if they should obey the laws of the land and God revealed to him that polygamy should be stopped.
The current prophet and president of the Church, Gordon B. Hinckley stated, “I wish to state categorically that this Church has nothing whatever to do with those practicing polygamy. They are not members of this Church. Most of them have never been members. They are in violation of the civil law. They know they are in violation of the law. They are subject to its penalties. The Church, of course, has no jurisdiction whatever in this matter.
“If any of our members are found to be practicing plural marriage, they are excommunicated, the most serious penalty the Church can impose. Not only are those so involved in direct violation of the civil law, they are in violation of the law of this Church.” Polygamy is also not allowed within the Church even in countries where it is allowed. The Church today teaches that marriage is strictly monogamous and no one can be a member of the Church and practice plural marriage.