All states have legal same-sex marriage, while others have the options of civil unions, domestic partnerships, or reciprocal beneficiary relationships.
The legal issues surrounding same-sex marriage in the United States are complicated by the nation's federal system of government.
According to the federal Government Accountability Office (GAO), more than 1,138 rights and protections are conferred to U.S. citizens upon marriage by the federal government;[1] areas affected include Social Security benefits, veterans' benefits, health insurance, Medicaid, hospital visitation, estate taxes, retirement savings, pensions, family leave, and immigration law.
As a result, shortly after Windsor was decided, a number of federal areas ranging from veteran benefits to immigration were clarified as applying equally to same-sex couples.
The movement to obtain civil marriage rights and benefits for same-sex couples in the United States began in the 1970s but remained unsuccessful for over forty years.
On May 17, 2004, Massachusetts became the first U.S. state and the sixth jurisdiction in the world to legalize same-sex marriage following the Supreme Judicial Court's decision six months earlier.
Some tribes have passed legislation specifically addressing same-sex relationships and some specify that state law and jurisdiction govern tribal marriages.
The formalities for entering a civil union and the benefits and responsibilities of the parties tend to be similar or identical to those relating to marriage.
After same-sex marriage became legal in Vermont, Connecticut, New Hampshire, Rhode Island, and Delaware, those states ceased to offer civil unions.
[9] According to data from the Human Rights Campaign Foundation, the majority of Fortune 500 companies provided benefits to same-sex partners of employees as of June 2006.