Final answer:
U.S. law only permits being married to one spouse at a time, known as monogamy, and marrying another while still married is considered bigamy, which is a felony.
Step-by-step explanation:
In the United States, the law permits being married to only one spouse at a time, which is known as monogamy. Practices where individuals marry more than one spouse are known as polygamy, which includes both polygyny (one man with multiple wives) and polyandry (one woman with multiple husbands). Polygamy is often associated with religious ideologies and social status, and most societies permitting polygamy are in northern Africa and east Asia. Conversely, the United States upholds the ideal of serial monogamy, where individuals may have multiple spouses over their lifetime but only one at a time. Bigamy, the act of entering into marriage while still married to another person, is a felony in most states in the U.S.