Most polygamy in the United States is done within the borders of Utah and Arizona. Many FLDS members live in the twin communities of Hildale, Utah, and Colorado City, Arizona. There are several religious groups in the United States that actively promote the practice of polygamy, or plural marriage. Most (but not all) claim some historical connection to early Mormonism, and frequently call themselves "Mormon Fundamentalists" or "Fundamentalist Mormons," a term that members of The Church of Jesus Christ of Latter-Day Saints (mainstream Mormons), who do not practice polygamy, often object to. The Church of Jesus Christ of Latter-Day Saints renounced polygamy in 1890 as part of the events enabling Utah to become a state of the United States. Today, the church will excommunicate any member found to be practicing polygamy, even in countries where polygamy is legal, thus, FLDS members are not members of the official Mormon church.
Some say that the Mormons had to denounce polygamy before Utah became a state. This may or may not be true, as the plans to make Utah a state were in action before the Church officially denounced polygamy. Either way, Mormons arrived there in 1847, Utah became a territory in 1850, Mormons ended polygamy in 1890, and Utah became a state in 1896.
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.
Utah was finally admitted in that year after agreeing to outlaw polygamy.
Utah
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.
One of the conditions for Utah to become a state was a ban on polygamy be written into the state constitution.
The Mormon Church banned polygamy in 1890, and Utah was admitted as a state in 1896. This wasn't the only condition to Utah's statehood, but it was a factor.
The State of Utah was formed on January 4, 1896. It would have become a state sooner but the polygamy laws of the Mormons violated the US Constitution.
You are probably thinking of Utah, but it was not admitted as a state until 1896.
Utah! the state brigham young founded in the early 1800's. it had started out as a territory, but in the 1880's, it became a state that had banned polygamy, and against common belief, has as many Mormons as not.
Utah
The Mormons in Utah Territory used to practice polygamy until the United States forced them to change that policy to become a state.