Same-sex marriage (also known as gay marriage) is marriage between two persons of the same biological sex or gender identity. Supporters of legal recognition for same-sex marriage typically refer to such recognition as marriage equality.
Since 2001, ten countries have begun allowing same-sex couples to marry nationwide: Argentina, Belgium, Canada, Iceland, the Netherlands, Norway, Portugal, Spain, South Africa, and Sweden. Same-sex marriages are also performed and recognized in Mexico City and parts of the United States. Some jurisdictions that do not perform same-sex marriages recognize same-sex marriages performed elsewhere: Israel, the Caribbean countries of the Kingdom of the Netherlands, parts of the United States, and all states of Mexico. Australia recognises same-sex marriages only by one partner changing their sex after marriage. A law legalizing same-sex marriage was passed by the parliament of Denmarkand is expected to come into force on June 15, 2012. The introduction of same-sex marriage has varied by jurisdiction, resulting from legislative changes to marriage laws, court challenges based on constitutional guarantees of equality, or a combination of the two. In some countries, allowing same-sex couples to marry replaced a previous system of civil unions or registered partnerships.
Consistently throughout the world, more-educated people are more likely to support same-sex marriage and its legalization than less-educated or uneducated people, and younger people support same-sex marriage more than older generations.
Same-sex marriage in the United States is not yet recognized by the federal government, but such marriages are recognized by some individual states. The lack of federal recognition was codified in 1996 by the Defense of Marriage Act, before Massachusetts became the first state to grant marriage licenses to same-sex couples in 2004. Such licenses are granted by six states:Connecticut, Iowa, Massachusetts, New Hampshire, New York, and Vermont, plus Washington, D.C. and Oregon's Coquille and Washington state's Suquamish Indian tribes. The states of Washington and Maryland have passed laws in 2012 to begin granting same-sex marriage licenses, but each may be delayed or derailed by November 2012 voter referendums. Same-sex marriages could be legally performed in California between June 16, 2008, and November 4, 2008, after which voters passed Proposition 8 prohibiting same-sex marriages. California also recognizes any same-sex marriage from around the world that took place before that end date, while Maryland and Rhode Island recognize all same-sex marriages from other jurisdictions. The legalization of same-sex marriage has been achieved by court rulings and legislative action, but not through voter referendums. As of May 2012, with the passing of North Carolina's gay marriage ban, 12 states prohibit same-sex marriage via statute and 30 via the state's constitution.
The movement to obtain marriage rights and benefits for same-sex couples in the United States began in the early 1970s. The issue became more prominent in U.S. politics in 1993 when the Hawaii Supreme Court decided Baehr v. Lewin (holding that the state's ban probably violated the state's Constitution), which prompted the U.S. Congress to pass the Defense of Marriage Act in 1996. Through the first decade of the 21st century, public support for its legalization grew considerably, and contemporary polls show that a majority of Americans support same-sex marriage. On May 9, 2012, Barack Obama became the first sitting U.S. president to publicly declare his support for the legalization of same-sex marriage.