Stanley Kurtz, an American conservative and member of the Hudson Institute, opposes the decriminalization and legalization of polygamy. Because polygamy has been illegal in the United States since the mid-19th century, and because it was illegal in many states before that time, sources on alternative marriage practices are limited. As a result, it is difficult to get a clear picture of the extent of practice, past and present. In 2001, Juab County District Attorney David O. Leavitt in Utah, USA, successfully prosecuted Thomas Green, who was convicted of criminal non-support and quadruple bigamy for contracting five serial monogamous marriages while living with legally divorced former wives. His cohabitation was considered proof of a common-law relationship with the wives from whom he had divorced while he was still living with them. This premise was later upheld by the Utah Supreme Court in State v. Green, as applicable only in the State of Utah. Green was also convicted of child rape and criminal lack of support.  The range of non-monogamous consensual relationships includes: polyamory (multiple romantic or sexual partners), polygamy (a person married to multiple partners), group marriage (each person in the relationship is married to the others), open relationship/marriage (a committed or married couple who are not committed to sexual fidelity), polyfidelity (a relationship with multiple partners but limits sexual activity to a specific group), monogamous (couples who are sexually polyamorous but remain “emotionally monogamous”), swinging (similar to open relationships, but performed as an organized social activity, often with some form of; sometimes called a woman/husband exchange), triad (a polyamorous relationship of three), and relationship anarchy (participants in the relationship are not bound by established rules or norms).
In 2007, the Attorney General of British Columbia raised concerns about the constitutionality of this prohibition, and an independent prosecutor in British Columbia recommended that Canadian courts be called upon to rule on the constitutionality of laws against polygamy.  The Supreme Court of British Columbia upheld section 293 of the Criminal Code against Polygamy of Canada and other related legislation in a 2011 reference.   On March 9, 2018, the Supreme Court of British Columbia upheld the constitutionality of Canada`s anti-polygamy laws.  A federal judge rejected the anti-polygamy law as unconstitutional. But a federal appeals court overturned the verdict and the U.S. Supreme Court refused to hear the case. Polygamy is the practice of having more than one spouse. In particular, polygamy is the practice of a man taking more than one wife, while polyandry is the practice of a woman taking more than one husband.
Polygamy is a common model of marriage in some parts of the world. In North America, polygamy is not a culturally normative or legally recognized institution since the colonization of the continent by Europeans. Couples have been married in the United States for centuries. For most of U.S. history, marriages were solemnly celebrated in a religious setting. State-issued marriage licenses are a modern innovation. Even before the advent of licensing, many states enacted laws prohibiting polygamy-type relationships. Early Mormons were persecuted for their polygamy. No state allows its citizens to enter into more than one simultaneous and legally permitted marriage. People who try to get a second marriage license are usually prosecuted for bigamy. The terms “bigamy” and “polygamy” are sometimes confused or used interchangeably.
The statutes of some states refer to polygamy, while others use the term bigamy. Criminal penalties vary considerably. Prosecutions for these two violations are extremely rare. Polygamy is a difficult practice to define, as it almost never occurs in the context of legal licensing. Since Mormon polygamists migrated to the Rocky Mountains in 1847, in part to avoid lawsuits for polygamy in the eastern states, efforts to curb the practice focused intensely on Utah and surrounding territories in the 1800s. Utah and four other Western territories were forced to include a ban on plural marriage in their state constitutions. In Christianity, the Roman Catholic Church condemns polygamy, as do most Protestant churches. However, the Lutheran Church accepts some polygamists and the Anglican Communion decided in 1988 that polygamy was permitted in certain circumstances. Polygamy usually takes the form of polygamy – when a man marries several wives. Polyandry, which refers to women with more than one husband, is even rarer than polygamy and is mostly documented in small, relatively isolated communities around the world. While polygamy laws are generally biased in favor of men – but not women – to take multiple spouses, the laws of many countries also speak in favor of women`s rights. In Burkina Faso, for example, where polygamy is common, spouses must agree that a marriage will be polygamous from the beginning so that the husband can take another wife in the future.
In Djibouti, a judge records the opinions of existing wives on new marriages and reviews the husband`s socio-economic situation before approving a marriage contract with another wife. The data on the prevalence of polygamous households was part of a Pew Research Center report on household composition by religion around the world. Not all people who practice polygamy live in polygamous households. Sometimes two or more wives of the same man each have their own home.