No. The Church of Jesus Christ of Latter-day Saints (the "Mormon" church) banned the practice of polygamy over 120 years ago in 1890. Anyone who has been found entering into a polygamous marriage since that time has been immediately excommunicated from the Church.
Those polygamists you see on TV shows and the news are what are called "Mormon Fundamentalists". Most of them belong to breakaway sects which split from the Mormon church at the time of the polygamy ban. Both the polygamous groups and the mainstream Mormon church try to separate themselves from each other in the public eye - the polygamists think that the mainstream Mormons are wrong, and the mainstream Mormons think the polygamists are wrong. For the most part, they don't want to be associated with each other.
No. Polygamy is illegal in the United States and has been since the 1860's. In Utah, just cohabiting with more than one person you are not legally related to is a felony punishable by several years in prison.
Faced with opposition in the eastern states, the early Mormons began to migrate to Utah in 1847. They continued to practise polygamy (or plural marriage) in Utah, until the practice was officially abandoned in 1890. However, polygamy was at all times illegal under United States law, so legally no one could practise polygamy in Utah.
Yes. Polygamy is illegal in China.
Yes. Polygamy was made illegal in the United States in 1862. The reason why is because some utopian societies and religious groups were practicing polygamy and the general public didn't like it so they made a law against it.
No, polygamy is illegal in Tennessee.
Yes. Polygamy is illegal in the United States. Each state has their own definition of what counts as polygamy.
Utah
No, polygamy is illegal in Washington state.
No. Polygamy is illegal everywhere in the United States.
No. Polygamy is illegal in all 50 states.
Polygamy is illegal in every state of the United States of America.
The United States government outlawed polygamy in all it's states and territories in 1865. As Utah was a territory at that time, polygamy was outlawed in Utah Territory by an act of the United States government.