Short answers, pulled from the story.
Polygamy is the practice of marrying multiple spouses simultaneously. Its three specific forms are polygyny (one man with multiple wives), polyandry (one woman with multiple husbands), and group marriage (multiple husbands and multiple wives forming a single family unit).
Of 1,231 societies recorded in the Ethnographic Atlas Codebook from 1960 to 1980, 588 practiced frequent polygyny, 453 had occasional polygyny, 186 were monogamous, and only 4 had polyandry. Later research identified at least 53 communities with some form of polyandry.
Burkina Faso, Mali, Gambia, Niger, and Nigeria are estimated to have the highest polygamy prevalence globally, located in a region researchers call the "polygamy belt" in West and Central Africa. Pew data place polygamy at 36 percent in Burkina Faso, 34 percent in Mali, and 28 percent in Nigeria.
Islamic marital jurisprudence permits a Muslim man to have up to four wives simultaneously, provided he treats them equally financially and in terms of support. Muslim women are not permitted to have more than one husband. The Quran in verse 4:3 advises monogamy for any man who fears he cannot be just to multiple wives.
LDS Church president Wilford Woodruff issued a public declaration known as the Manifesto in 1890, announcing that the church had discontinued new plural marriages. A Second Manifesto followed in 1904 after the Smoot Hearings, and by 1910 the church excommunicated those who entered into or performed new plural marriages.
Polygamy is illegal in all 50 US states. The Supreme Court upheld federal anti-polygamy legislation as constitutional in Reynolds v. United States in 1878. Utah downgraded polygamy from a felony to an infraction in 2020, but it remains a felony when force, threats, or other abuses are involved, and recognizing polygamous unions is still prohibited under Utah's constitution.