State laws traditionally govern who can marry and, in turn, how a marriage can be ended. An individual's marital status, in turn, is key to how he or she fits into the federal matrix of benefits, parental rights and financial standings.

Recent moves by state courts and legislatures to further define whether marriage can extend to same-sex couples has inspired new questions about how states regulate the institution in the future, and what role the federal government should play in such regulation.

In early 2004, President Bush said he supported amending the U.S. Constitution to ban marriages between same-sex couples.

The president said he would like to see an amendment "defining and protecting marriage as a union of a man and woman, as husband and wife" but also added that states should have the right to outline "legal arrangements other than marriage."

The growing collision of state and federal regulations over the definition of marriage may ultimately lead the U.S. Supreme Court to evaluate the varying stances on marriage and how they should apply to the gay community.

Basics of marriage and American law
American law and its core marriage regulations are largely grounded in British common law. Those traditions viewed marriage as a voluntary contract between a man and a woman to become husband and wife. Marriage also confirmed the legitimacy of the couple's children.

In the mid-1800s, laws and statutes regarding personal property and women's rights were changed to give both partners more equal legal footing.

Many state-level marriage regulations are administrative, such as requiring a minimum age or requiring blood tests to apply for a marriage license. Other state-specific regulations prohibit relatives from marrying each other.

Once an individual is married, there are certain legal steps or circumstances that must occur for the union to be dissolved or for that person to remarry. These include death, divorce and annulment.

The legal and financial implications of state marriage laws have been amended and added as society has changed over time -- including a large number of states that have moved to prohibit a person from marrying someone of the same sex.

One of the most significant changes at the federal level was the 1996 passage of the Defense of Marriage Act. Under DOMA, states would not be required to recognize same-sex marriages performed in another state. The act defined marriage as "the legal union between one man and one woman as husband and wife."

On the heels of DOMA's passage, 38 states went on to pass their own "marriage protection" statutes that define marriage as occurring between one man and one woman, and denying recognition of same-sex marriages or civil unions performed in other states.

The ramifications of a same-sex couple not being able to legally marry are more than symbolic -- some 1,049 federal laws include marital status as a factor, according to a 1997 report from the U.S. General Accounting Office.

The types of rights and benefits for married couples that are denied to same-sex couples include property rights, health care benefits, child custody, immigration, inheritance and hospital visitation.

Some states have also adopted additional "covenant marriage" legislation, which goes a step further in solidifying the bonds of marriage. Covenant marriage is an option for those who do not believe in swift no-fault divorce or wish to demonstrate a stronger level of commitment to their marriage bond. Generally, couples who choose to enter a covenant marriage must attend premarital counseling and may only divorce after two years of separation or being able to prove specific circumstances for the split, such as abuse or adultery.

Louisiana was one of the first states to pass a covenant marriage law in 1997. A little over 1 percent of couples married in the state from 1998-2002 opted for the provision, according to media reports.

Court battles over state same-sex marriage laws
As states have sought to define their rules on same-sex unions, legal battles over whether homosexual couples can be refused a marriage license have largely played out in the state courts and legislatures over the last decade.

State courts in Hawaii, Alaska and Vermont were among the first to weigh in on the issue of whether their states had the right to refuse marriage certificates to gay couples. To date, no American court has ever ordered the issuance of a marriage license to a same-sex couple.

In the 1993 case Baehr v. Lewin, the Hawaii Supreme Court ruled that statutes prohibiting a person from marrying someone of the same sex might violate the state constitution.

As the case moved through the court system, the Hawaii Legislature proposed an amendment to the state constitution to give the legislature the power to reserve marriage to opposite-sex couples. Voters in Hawaii approved the marriage amendment during November 1998 elections.

The Hawaii legislature went on to enact a law recognizing "reciprocal beneficiary" relationships that would allow couples who cannot marry to register as reciprocal beneficiaries and receive some of the benefits afforded married couples.

The Vermont Supreme Court ruled in the 1999 case State v. Baker that the state constitution allowed same-sex couples to obtain the same benefits as married couples. The state legislature went on to enact a law giving same-sex couples virtually all the same rights and protections as married couples.

Vermont is currently the only state that grants same-sex couples the same state-granted rights and benefits as heterosexual married couples, although the state terms their partnerships "civil unions" instead of marriages.

Some federal benefits, such as Social Security and Medicaid, remain unavailable as DOMA dictates.

Benefits granted to same-sex couples according to state
Hawaii, California, Massachusetts and New Jersey are currently the only other states to formally recognize "domestic partnerships" allowing same sex couples to apply for some of the state-run benefits afforded to the married.

Each of these states is unique in terms of what state benefits same-sex couples can apply for if they meet the domestic partnership criteria. Hawaii, for example, offers multiple benefits for partners of state employees but does not offer property division or alimony rights as a marriage would. Simply filing a declaration with the proper authorities can terminate a reciprocal beneficiary relationship in the state.

New Jersey, the state that has passed the most recent domestic partnership law, allows same-sex couples to claim joint status for state taxes and may claim some medical insurance and pension benefits if their partner works for the state.

New Jersey and California have similar criteria to qualify for a domestic partnership: Same-sex couples must share a common residence and be in a committed relationship of "mutual caring." An opposite-sex couple over age 62 can also apply for domestic partnership status.

Massachusetts has taken a critical role in the legal debate over whether states can allow same-sex couples to marry. After seven couples sued for the right to wed, the Massachusetts Supreme Judicial Court ruled in November 2003 that barring same-sex couples from marriage was unconstitutional.

In a subsequent February 2004 decision, the court ruled 4-3 to give the state legislature six months to rewrite the state's marriage laws to accommodate gay couples. Legislators are considering an amendment to the state constitution that would ban gay marriage but could permit civil unions.

"Marriage is a vital social institution. The exclusive commitment of two individuals to each other nurtures love and mutual support. It brings stability to our society," Chief Justice Margaret Marshall wrote in the ruling.

In February 2004, San Francisco decided to strike out on its own, and began issuing marriage licenses to gay couples. Same-sex couples flocked to City Hall, waiting in long lines in the hopes of obtaining a license.

"We are reading the direct language within the state constitution, and we directed our county clerk to do the right thing and extend the privilege that's extended to my wife and myself and millions of us across the country to same-sex couples," San Francisco Mayor Gavin Newsom told CNN in mid-February.

San Francisco issued over 4,000 marriage licenses to same-sex couples between Feb. 11 and March 11, when the California Supreme Court ordered City Hall to stop. The issue continues to play out in a lawsuit currently in the California Superior Court.

California has one of the highest concentrations of gay households in the country at 1.4 percent of the total number of coupled households, according to an Associated Press analysis of the 2000 census. In Massachusetts, same-sex partners occupy 1.3 percent of coupled households. Vermont and New York also registered at 1.3 percent.

Lawmakers' role in the debate
The White House's decision to support a constitutional amendment comes after most state legislatures have sought to better define their laws on marriage and its parameters.

In most states, lawmakers are considering proposed amendments to their constitutions that would define existing prohibitions on same-sex marriage and deny recognition of unions that may be allowed elsewhere in the country.

In Alabama, for example, a constitutional amendment is pending action in the House of Representatives but some lawmakers want to delay putting it on the ballot until 2006, to avoid its potentially polarizing role in the 2004 presidential election.

In Indiana, a proposed state constitutional ban on gay marriage passed in the Senate, but Democratic Speaker Patrick Bauer shelved the measure in the House, prompting House Republicans to walk out.

Most states continue to consider legislative proposals, with varying levels of debate and attention.

Some members of the U.S. Congress have pointed to the battles in the state-level courts and the decisions of individual judges as part of the need for a U.S. constitutional amendment.

"Why is an amendment necessary? Two words: activist judges. The only way to save laws deemed unconstitutional by activist judges is a constitutional amendment," Sen. John Cornyn, R-Texas, said during a hearing of the Senate Subcommittee on Constitutional Law in March 2004.

-- By Maureen Hoch, Online NewsHour