Marriage is a legally sanctioned contract between a man and a woman. Entering a marriage contract changes the legal status of both parties, giving husband and wife new rights and obligations. 

Individuals who seek to alter marital rights and duties are permitted to do so only within legally prescribed limits. Pre-marital agreements are entered into before marriage, in contemplation of the marriage relationship. Typically these agreements deal with property rights and the terms that will be in force if a couple's marriage ends in divorce.  

In the United States, marriage is regulated by the states. At one time most states recognized common-law marriage, which is entered into by agreement of the parties to be husband and wife. Most states have abolished common-law marriage, in large part because of the legal complications that arose concerning property and inheritance.

The idea that marriage is the union of one male and one female has been thought to be so basic that it is not ordinarily specifically expressed by statute. This traditional principle has been challenged by gays and lesbians who, until recently, have unsuccessfully sought to legalize their relationships. 

Each state has its own individual requirements concerning who can marry. Before a state will issue a marriage license, a man and a woman must meet certain criteria. Some states prohibit marriage for those judged mentally ill or mentally retarded. In other states, however, a judge may grant permission to mentally retarded persons to marry.

Every state proscribes marriage between close relatives on the basis of the social taboo of incest. The prohibited degree of relationship is fixed by state law. Every state forbids marriage to a child or grandchild, parent or grandparent, uncle or aunt, and niece or nephew, including illegitimate relatives and relatives of half blood, such as a half brother who has the same father but a different mother. A number of states also prohibit marriage to a first cousin, and some forbid marriage to a more distant relative, in-law, stepparent, or stepchild.

Age is an additional requirement. Every jurisdiction mandates that a man and a woman must be old enough to wed. Modern statutes ordinarily provide that females may marry at age sixteen and males at age eighteen. 

Every couple that wishes to marry must comply with a state's formal requirements. Many states require a blood test or a blood test and physical examination before marriage to show whether one party is infected with a venereal disease.

Most states impose a waiting period between the filing of an application for a license and its issuance. The period is usually three days, but in some states the period may reach five days. 

Once a license is issued, the states require that the marriage commence with a wedding ceremony. The ceremony may either be civil or religious because states cannot require religious observances. Ceremonial requirements are very simple and basic to accommodate everyone. In some states nothing more is required than a declaration by each party in the presence of an authorized person and one additional witness that he or she takes the other in marriage.

Article on the Legal Effects of Marriage
Another Article on the Legal Effects of Marriage
Marriage Requirements
How to Obtain Birth, Death and Marriage Certificates
Common Law Marriage
Premarital Agreements
Same Sex Marriage and Domestic Partnership
Domestic Partnership Benefits
Living Together Contracts