The basis for what legally defines marriage is in the law of contract. However, as with all laws that define one’s status, the fundamental laws of the land protect one’s personal rights and freedoms. In America, the U.S. Constitution guarantees individual rights. Marriage is a matter of state law, but federal laws have shaped it through Constitutional court decisions that define a person’s rights to due process of law, to equal treatment under the laws. Thus, marriage is a matter of state law but to the extent that it involves fundamental rights, it is subject to Constitutional principles of equality.
A marriage is a union of physical, moral, and legal commitments. A spouse has distinct legal status, to act for the other in certain situations, and to receive benefits defined as spousal benefits. A spouse is a legal status above next of kin. A spouse has rights over joint property and can act for the other in situations of disability, impairment, or death. By law, many individual benefits also belong to the spouse. For example, a surviving spouse has a right to Federal Social Security benefits. According to the Government Accounting Office, there are more than 1,000 such benefits under federal and state law triggered by the status of lawful spouse, such as insurance, healthcare, pensions, and employment. The IRS has also redefined marriage for tax purposes.
In the event of death, the law provides for distribution of most property to a surviving spouse in the absence of a Will. A spouse can make medical decisions for an unconscious partner or in situations when one unable to make decisions for his or herself. A spouse has unique standing to testify in court proceedings if against the interests of a marriage partner.
Marriage is lawful between consenting adults regardless of gender or sexual orientation in the United States. This is a growing trend around the world as sexual orientation has fallen into disfavor as a basis for treating some citizens differently than others by denying a right to marriage; many nations recognize same-sex marriage. In the U.S., many states have recognized same-sex marriages. Federal law still leaves it to the states to define marriage, however, federal standards, if violated, result in successful challenges to discriminatory state law.
Marriage has traditionally been limited to unions between one man and one woman. Religious traditions have had a large role in public policy, but the law does not follow religious principles. For example, some churches recognize marriage but not divorce. Other religions permit marriages between one man and several women. In the United States, laws require a valid marriage license, and a state government issues it. Performed as ceremonies in churches, mosques, or synagogues, in order to be valid, a state- authorized person must perform the marriage.
ACLU: DOMA Unconstitutional
GAO: Spouse Benefits
U.S. Department of the Treasury, IRS