bigamy (bĭˈgəmē) [key], crime of marrying during the continuance of a lawful marriage. Bigamy is not committed if a prior marriage has been terminated by a divorce or a decree of nullity of marriage. In the United States if a husband or wife is absent and unheard of for seven (or in some states five) years and not known to be alive, he or she is presumed dead, and remarriage by the other spouse is not bigamous. It is not necessarily a defense to a charge of bigamy that the offending party believed in good faith that he was divorced or that his previous marriage was not lawful.
The U.S. Supreme Court ruled in 1878 that plurality of wives (polygamy), as originally permitted by the Mormon religion, violated criminal law and was not defensible as an exercise of religious liberty. The Latter-day Saints renounced polygamy in 1890, but the practice has persisted among some, although it has been rarely prosecuted.