1995 Utah becomes the first state to enact a Defense of Marriage Act (DOMA). Several other states previously had approved statutes defining marriage as between one man and one woman.

1996 President Clinton signs the federal Defense of Marriage Act, upholding states’ right to ban same-sex marriage and prohibiting the federal government from recognizing same-sex marriage.

1997 Hawaii becomes the first state to offer same-sex couples domestic partnership benefits.

1998 Alaska voters approve a constitutional amendment banning same-sex marriage. Hawaii voters approve constitutional language allowing their legislature to determine policy on same-sex marriage, effectively overturning a series of earlier court decisions that may have required the state to allow gay and lesbian couples to wed. The legislature subsequently approves a measure banning same-sex marriage.

1999 California enacts a law allowing gay and lesbian couples to register as domestic partners. The Vermont Supreme Court rules that same-sex couples are entitled to the same benefits and protections as married heterosexual couples. The decision prompts the state to enact a law in 2000 allowing gay and lesbian couples to enter into civil unions.

2000 Nebraska voters approve a constitutional amendment banning same-sex marriage. California voters approve Proposition 22, which bans same-sex marriage in state law.

2001 Americans oppose same-sex marriage by a 57% to 35% margin. By 2013, there is slightly more support for same-sex marriage than opposition to it, with 50% in favor and 43% opposed.

2002 Nevada voters approve a constitutional amendment banning same-sex marriage.

2003 The Massachusetts Supreme Judicial Court rules that the state constitution gives gay and lesbian couples the right to marry, making the Bay State the first in the nation to allow same-sex marriage. Weddings begin in 2004. The Federal Marriage Amendment, which would add language to the U.S. Constitution banning same-sex marriage nationwide, is introduced in the U.S. House of Representatives.

2004 Local officials in California, New York, New Mexico and Oregon allow same-sex couples to marry. Those licenses ultimately are invalidated. Voters in Arkansas, Georgia, Kentucky, Louisiana, Michigan, Mississippi, Missouri, Montana, North Dakota, Ohio, Oklahoma, Oregon and Utah approve constitutional amendments banning same-sex marriage.

2005 Voters in Kansas and Texas approve constitutional amendments banning same-sex marriage.

2006 New Jersey enacts a law allowing same-sex couples to enter into civil unions. Voters in Alabama, Colorado, Idaho, South Carolina, South Dakota, Tennessee, Virginia and Wisconsin approve constitutional amendments banning same-sex marriage. Voters in Arizona reject a constitutional amendment that would have banned same-sex marriage, marking the first time such a measure has been rejected by voters.

2007 New Hampshire enacts a law allowing same-sex couples to enter into civil unions. California Gov. Arnold Schwarzenegger vetoes legislation that would have legalized same-sex marriage in his state.

2008 The Connecticut Supreme Court rules that the state’s constitution guarantees same-sex couples the right to marry, making Connecticut the second state to allow gay and lesbian couples to wed. The Supreme Court of California rules that the state’s constitution guarantees same-sex couples the right to marry. Later in the year, however, California voters approve a constitutional amendment (known as Proposition 8) banning same-sex marriage. Voters in Arizona and Florida approve constitutional amendments banning same-sex marriage.

2009 The Iowa Supreme Court rules that the state’s constitution guarantees same-sex couples the right to marry, making Iowa the third state to allow gay and lesbian couples to wed. New Hampshire Gov. John Lynch signs a bill legalizing same-sex marriage. The Vermont legislature overrides Gov. Jim Douglas’ veto to approve a law legalizing same-sex marriage. District of Columbia Mayor Adrian Fenty signs a bill legalizing same-sex marriage.

2010 A federal district court in Massachusetts rules that the part of the Defense of Marriage Act that prohibits the federal government from recognizing same-sex marriage is unconstitutional. A federal district court in California rules that Proposition 8 violates the U.S. Constitution.

2011 Hawaii enacts a law allowing same-sex couples to enter into civil unions. New York Gov. Andrew Cuomo signs a bill legalizing same-sex marriage, making the Empire State the sixth in the nation to allow gay and lesbian couples to wed.

2012 Barack Obama becomes the first sitting president to announce his support for same-sex marriage. Voters in Maine, Maryland and Washington state approve laws legalizing same-sex marriage, becoming the first states to do so through popular votes. Voters in Minnesota reject a constitutional amendment that would have banned same-sex marriage. Voters in North Carolina approve a constitutional amendment banning same-sex marriage.

2013 The Supreme Court strikes down part of the federal Defense of Marriage Act, requiring the federal government to recognize same-sex marriages from the states where they are legal. The Supreme Court declines to rule on the merits of the case involving Proposition 8, California’s constitutional ban on same-sex marriage, saying that those defending Proposition 8 did not have the legal standing to do so. Same-sex marriages begin again in California. Governors in Delaware, Hawaii, Illinois, Minnesota and Rhode Island sign bills legalizing same-sex marriage. Courts in New Jersey and New Mexico issue rulings that allow same-sex couples to wed.

2014 A series of federal court decisions strike down same-sex marriage bans in several states, and the Supreme Court declines to review cases in Indiana, Oklahoma, Utah, Virginia and Wisconsin, effectively requiring those states to allow gay and lesbian couples to wed. Other federal court rulings make same-sex marriage legal in Oregon, Pennsylvania, Colorado, Nevada, Alaska, Idaho, West Virginia, North Carolina, Arizona, Wyoming, Kansas, South Carolina and Montana. At the same time, however, the 6th Circuit Court of Appeals becomes the first — and so far only — federal appeals court to uphold state gay marriage bans, a ruling that applies to Michigan, Ohio, Kentucky and Tennessee. The decision also makes it likely that the Supreme Court will soon rule on the constitutionality of gay marriage bans.