The term “bigamy” refers to the crime of getting married to another person with the knowledge that one party or the other is already married to someone else. A bigamous marriage is void ab initio and bigamy is grounds for annulment.

In Reynolds v. United States, 98 U.S. 145 (1878), the U.S. Supreme Court upheld the constitutionality of a law forbidding polygamy even though Mormons claimed that it was required by their religion.  The Court reasoned that, “as a law of the organization of society under the exclusive dominion of the United States, it is provided that plural marriages shall not be allowed.  Can a man excuse his practices to the contrary because of his religious belief?  To permit this would be to make the professed doctrines of religious belief superior to the law of the land, and in effect to permit every citizen to become a law unto himself.  Government could exist only in name under such circumstances.”  Id. at 166-167.

(n) A criminal offense when one person marries more than once (usually for the second time). Once the first marriage has been verified to be valid, all the other succeeding marriages are null. Although bigamy is a crime, a committer of this offense often goes unpunished, unless the marrying is part of a grand plan as in getting the partner’s property through conjugal law. There are some instances too when a person can commit bigamy unintentionally, this happens when he/marries believing that the original marriage is already invalidated. One outstanding case in the United States is the Jackson – Robards case.
Andrew Jackson and his spouse Rachel Robards applied for divorce, but it was denied at the time of a succeeding marriage. This is sensationalized because Jackson, being a lawyer and a judge is a hand of law. Having more than one wives, is called polygamy while having many husbands is called polyandry – both are punishable by law.

Reference Desk

 Black’s Law Dictionary, 2nd Eidition.

The criminal offense of willfully and knowingly contracting a second Q marriage (or going through the form of a second marriage) while the first marriage, to the knowledge of the offender, is still subsisting and undissolved. Com. v. McNerny, 10 Phila. (Pa.) 207; Gise v. Com., 81 Pa. r 430; Scoggins v. State, 32 Ark. 213; Cannon t v. U. S., 116 U. S. 55, 6 Sup. Ct 287, 29 L. Ed. 561. The state of a man who has two wives, or of a woman who has two husbands, living at the same time. C The offense of having a plurality of wives at the same time is commonly denominated “polygamy;” but the name “bigamy” has been more frequently given to it in legal proceedings. 1 Russ. Crimes, 185. p The use of the word “bigamy” to describe this U offense is well established by long usage, although often criticised as a corruption of the true meaning of the word. Polygamy is suggested as the correct tenn. instead of bigamy, to designate the offense of having a plurality of wives or husbands at the same time, and has M been adopted for that purpose in the Massa- II chusetts statutes. But as the substance of the offense is marrying a second time, while having a lawful husband or wife living, without regard to the number of marriages that may have taken place, bigamy seems not an inappropriate term. The objection to its use urged by Black- I stone (4 Bl. Comm. 163) seems to be founded I not so much upon considerations of the etymology of the word as upon the propriety of distinguishing the ecclesiastical offense termed “bigamy” in the canon law, and which is defined below. from the offense known as “bigamy” in the modern criminal law. The same distinction is t carefully made by Lord Coke. (4 Inst. S8.) But, I the ecclesiastical offense being now obsolete, this reason for substituting polygamy to denote the crime here defined ceases to have weight. Abbott. In the canon law, the term denoted the .. offense committed by an ecclesiastic who | married two wives successively. It might be committed either by marrying a second wife after the death of a first or by marrying a widow.

 Encyclopedia Britannica, 11th Edition.

BIGAMY (from Lat. bis, twice, and Gr. yaµos, marriage), in English law, according to the statute now in force (24 and 25 Vict. c. loo, § 57), the offence committed by a person who “being married shall marry any other person during the life of the former husband or wife.” In the canon law the word had a rather wider meaning, and the marriage of a clerk in minor orders with a widow came within its scope. At the council of Lyons (A.D. 1274) bigamists were stripped of their privilege of clergy. This canon was adopted and explained by an English statute of 1276; and bigamy, therefore, became a usual counterplea to the claim of benefit of clergy. However, by an act of 1547 every person entitled to the benefit of clergy is to be allowed the same, “although he hath been divers times married to any single woman or single women, or to any widow or widows, or to two wives or more.” A bigamous marriage, by the ecclesiastical law of England, is simply void. By a statute of 1604 the offence was made a felony. This statute, after being repealed in 1828, was re-enacted and reproduced in the Offences against the Person Act 1861. It is immaterial whether the second marriage has taken place within England and Ireland or elsewhere, and the offence may be dealt with in any county or place where the defendant shall be apprehended or be in custody. The following clause embodies the necessary exceptions to the very general language used in the definition of the offence: – “Provided that nothing in this section contained shall extend to any second marriage contracted elsewhere than in England and Ireland by any other than a British subject, or to any person marrying a second time whose husband or wife shall have been continuously absent from such person for the space of seven years then last past, and shall not have been known by such person to be living within that time, or shall extend to any person who at the time of such second marriage shall have been divorced from the bond of the first marriage, or to any person whose former marriage shall have been declared void by any court of competent jurisdiction.” The punishment is penal servitude for not more than seven nor less than five years, or imprisonment with or without hard labour, not exceeding two years.

A valid marriage must be proved in the first instance in order to support a charge of bigamy. A voidable marriage, such as were marriages between persons within the prohibited degrees before the Marriage Act 1836, will be sufficient, but a marriage which is absolutely void as all such marriages now are, will not. For example, if a woman marry B during the lifetime of her husband A, and after A’s death marry C during the lifetime of B, her marriage with C is not bigamous, because her marriage with B was a nullity. In regard to the second marriage (which constitutes the offence) the English courts have held that it is immaterial whether, but for the bigamy, it would have been a valid marriage or not. An uncle, for example, cannot marry his niece; but if being already married he goes through the ceremony of marriage with her he is guilty of bigamy. In an Irish case, however, it has been held that to constitute the offence the second marriage must be one which, but for the existence of the former marriage, would have been valid. With reference to the case in which the parties to the first marriage have been divorced, it may be observed that no sentence or act of any foreign country dissolving a vinculo a marriage contracted in England by persons continuing to be domiciled in England, for grounds on which it is not liable to be dissolved a vinculo in England will be recognized as a divorce (R. v. Lolley 1812, R. & R. 237). Hence, a divorce a vinculo for adultery, in a Scottish court, of persons married in England, is not within the statute. But if a person charged with bigamy in England can prove that he has been legally divorced by the law of the country where the divorced parties were domiciled at the time (even though the ground on which the divorce was granted was not one that would justify a divorce in England) it will be good defence to the charge. Criminal jurisdiction is always regarded as purely territorial, but bigamy (together with homicide and treason) is an exception to this rule. A British subject committing bigamy in any country may be tried for the same in the United Kingdom (Earl Russell’s case, 1901).

In Scotland, at the date of the only statute respecting bigamy, that of 1551, cap. 19, the offence seems to have been chiefly considered in a religious point of view, as a sort of perjury, or violation of the solemn vow or oath which was then used in contracting marriage; and, accordingly, it was ordained to be punished with the proper pains of perjury.

Bigamy was punished in England until the reign of William III. by death, then the penalty changed to life imprisonment and branding of the right hand. An act of George I. still in force lessened the penalty to deportation for seven years or imprisonment for two years with or without hard labour. The Offences against the Person Act 1861 changed deportation to penal servitude.

In the United States the law in regard to bigamy is practically founded on the English statute of 1604, with the exception that imprisonment and a fine, varying in the different states, were substituted instead of making the offence a felony. Congress has passed a statute declaring bigamy within the territories and places within the exclusive jurisdiction of the United States to be a misdemeanour (U.S. Rev. Stat. § 535 2). By statute in some states, upon absence cf one spouse from the state for five years without being heard of, the other may marry again without committing bigamy, in other states the period is seven years. In most of the states, prosecutions for bigamy are barred after the lapse of a certain number of years. The marriage wherever solemnized must be a valid marriage according to the law of the place of solemnization; if void there, no prosecution for bigamy can be founded upon it. In some jurisdictions, an honest belief that a prior divorce of one of the parties was valid would be a defence to a prosecution for bigamy, in others the contrary is held.

On the continent of Europe, bigamy is punishable in most countries with varying terms of imprisonment, with or without hard labour, according to the circumstances of the case.

See Stephen, History of Criminal Law; Dicey, Conflict of Laws; Report of the Royal Commission on Marriage Laws (1868).

WordNet 3.6

(n) bigamy the offense of marrying someone while you have a living spouse from whom no valid divorce has occurred

(n) bigamy having two spouses at the same time

 Webster’s Revised Unabridged Dictionary

(n) Bigamy (Law) The offense of marrying one person when already legally married to another.☞ It is not strictly correct to call this offense bigamy: it more properly denominated polygamy, i. e., having a plurality of wives or husbands at once, and in several statutes in the United States the offense is classed under the head ofpolygamy. In the canon law bigamy was the marrying of two virgins successively, or one after the death of the other, or once marrying a widow. This disqualified a man for orders, and for holding ecclesiastical offices. Shakespeare uses the word in the latter sense.
“Base declension and loathed bigamy .”

Century Dictionary and Cyclopedia

(n) bigamy Literally, double marriage; remarriage during the existence of a former marriage; in law, the offense of having two or more wives or husbands at the same time. To constitute the offense, which by statute law is a felony, it is necessary, by the law of many jurisdictions, that the accused should have actual or constructive knowledge that the first wife or husband was still living when the second one was taken, and that the second marriage should have been one solemnized under the forms of law, and not merely an informal marriage resting on the contract of the parties, or their holding out each other to the world as husband and wife. Where these elements of knowledge and of formality are wanting, the second marriage is still generally invalid, but not bigamous in the criminal sense.
(n) bigamy Second marriage; remarriage of a widow or widower. In the early church, before the establishment of clerical celibacy, such remarriage on the part of a man was generally regarded as an impediment to holy orders. Marriage with a widow is called bigamy by Shakspere in Richard III., iii. 7.