In light of the rulings, here's a summary of the laws on same-sex marriage in all 50 states, and a look at how the Supreme Court action might affect them:
SAME-SEX MARRIAGE STATES:
CALIFORNIA: The Supreme Court cleared the way for gay marriages to resume in California for the first time since 2008, ruling that sponsors of the state's voter-approved same-sex marriage ban lack authority to defend it in court. A federal appeals court on Friday lifted the stay on same-sex marriages, saying the state is required to issue licenses to gay couples starting immediately.
CONNECTICUT: The state Supreme Court legalized same-sex marriage in October 2008; marriages started the next month.
DELAWARE: A same-sex marriage bill was signed into law in May. A Democratic state senator and her partner will be the first couple in the state to have their civil union converted to marriage when the bill takes effect July 1.
DISTRICT OF COLUMBIA: The D.C. Council approved same-sex marriage in 2009; marriages began in March 2010.
IOWA: The state Supreme Court legalized same-sex marriage in 2009. Conservative lawmakers have sought to change state law to define marriage as between a man and a woman. Those efforts have failed so far because Democrats controlling the state Senate have blocked any legislation from coming up for a vote. That's unlikely to change unless the GOP takes control of both chambers in 2014.
MAINE: Voters approved same-sex marriage last November, reversing results of a 2009 referendum that quashed a gay-marriage bill.
MARYLAND: The Legislature approved same-sex marriage in February 2012; the issue then won voter approval in a referendum last November.
MASSACHUSETTS: It was the first state to allow same-sex marriage. The state's Supreme Judicial Court ordered it legalized in 2003; marriages started in May 2004.
MINNESOTA: A same-sex marriage bill was signed into law in May. It takes effect Aug. 1.
NEW HAMPSHIRE: The Legislature approved same-sex marriage June 2009.
NEW YORK: The Legislature approved same-sex marriage in June 2011.
RHODE ISLAND: A same-sex marriage bill was signed into law in May. It takes effect Aug. 1.
VERMONT: The Legislature legalized same-sex marriage in 2009. Earlier, Vermont was the first state to offer civil unions to gay and lesbian couples.
WASHINGTON: The Legislature approved same-sex marriage in February 2012. It then won voter approval in referendum on Nov. 6, 2012.
CIVIL UNION STATES:
COLORADO: Gay-rights advocates were pleased that Colorado lawmakers approved a civil-union law this year that extends marriage-like rights to same-sex couples. But they still plan to push for the full status of marriage. That would entail either a lawsuit or a voter initiative to overturn a gay-marriage ban approved by voters in 2006.
HAWAII: Lawmakers passed a civil union law in 2011. It's being challenged in the 9th U.S. Circuit Court of Appeals by two women who want to marry rather than enter into a civil union. Democratic Gov. Neil Abercrombie supports same-sex marriage and says the U.S. Supreme Court rulings bolster his argument that the Constitution requires it.
ILLNOIS: Lawmakers approved civil unions in 2011, but an effort this year to legalize gay marriage fell short despite a push from Gov. Pat Quinn and Chicago Mayor Rahm Emanuel. The bill's sponsor, Democratic Rep. Greg Harris, says the Supreme Court rulings improve the chances in the next legislative session. Meanwhile, a right-to-marry lawsuit filed by more than two dozen gay couples is pending.
NEW JERSEY: Acting under an order from the state Supreme Court, the Legislature legalized civil unions in 2006. However, a pending lawsuit contends that civil unions do not fulfill the court's mandate that gay couples receive equal treatment. A hearing is scheduled for August. The Democratic-led Legislature passed a bill last to recognize gay marriage, but it was vetoed by Republican Gov. Chris Christie.
STATES WITH CONSTITUTIONAL BANS:
ALABAMA: Voters overwhelming approved a constitutional amendment in 2006 limiting marriage to one-man, one-woman unions. Democratic Rep. Patricia Todd, the only openly gay member of the Legislature, says she and her partner plan to file suit challenging the ban. "The state only moves forward on civil rights issues when forced by the federal courts," she says.
ALASKA: Voters approved a ban in 1998. Changing the constitution would requires that voters approve a constitutional convention -- but they opted not to do so in 2012. The Legislature also could propose a constitutional amendment, but Republicans control both chambers, and there is no apparent rush to act. Alaska's U.S. senators, Democrat Mark Begich and Republican Lisa Murkowski, support same-sex marriage. But the state's lone U.S. House member, Republican Don Young, and its GOP governor, Sean Parnell, do not.
ARIZONA: Gay-rights activists are gathering signatures in hopes of placing a measure on next year's ballot that would overturn a 2008 ban. Republican Gov. Jan Brewer predicts voters will reject any such effort. One city, Bisbee, recently legalized local-level civil unions for same-sex couples. Tempe and several other cities are considering similar ordinances.
ARKANSAS: The gay-rights group Arkansans for Equality is asking the state attorney general's office to approve language for a ballot measure next year that would repeal the 2004 ban on gay marriage. The attorney general must certify the language before the group can begin collecting the 78,133 signatures from registered voters needed to place it on the 2014 ballot.
COLORADO: As noted above, gay marriage is banned under a constitutional amendment approved by voters in 2006. But Democrats now control the Legislature and passed the bill this year establishing civil unions. Gay-rights supporters are deliberating on how to challenge the ban -- it could be through a lawsuit or a voter initiative.
FLORIDA: Voters approved a constitutional amendment banning same-sex marriages in 2008. It would take approval from 60 percent of voters to overturn it if the issue gets on the ballot again. That would require either action by the Legislature -- which seems unlikely anytime soon -- or a petition drive that would require the signatures of more than 683,000 registered voters.
GEORGIA: A gay-marriage ban was approved in 2004 with support from 76 percent of the voters. No group has mounted a serious attempt to overturn that prohibition. Most politicians in Georgia publicly embrace positions opposing gay-rights measures, although Atlanta Mayor Kasim Reed announced in December that he supports gay marriage.
IDAHO: Voters approved a ban in 2006 with 63 percent support. The Republican dominated Legislature is not expected to make any changes in the near future. GOP lawmakers have resisted appeals from gays to amend the Idaho Human Rights Act to include discrimination protections for gays and lesbians in regard to employment and housing.
KANSAS: Voters overwhelmingly approved a gay-marriage ban in 2005. With conservative Republicans in charge of both the House and Senate, no move to modify or repeal the amendment is expected.
KENTUCKY: Voters approved a ban in 2004; there's no serious talk of any imminent challenge. Chris Hartman, director of the Louisville-based Fairness Campaign, said the Supreme Court rulings may add momentum to the push for a state law protecting gays from discrimination in employment, housing and public accommodations.
LOUISIANA: A ban was approved by voters in 2004 with 78 percent support. Gay rights leaders say they will study the possibility of a challenge, but none is currently foreseen. Meanwhile, they will continue to lobby the Legislature for adoption rights and job protections.
MICHIGAN: A lawsuit to overturn a 2004 ban on same-sex marriage is pending in federal court. Detroit-area nurses April DeBoer and Jayne Rowse are suing to try to win the right to jointly adopt each other's children, and a judge suggested the case be stretched to include a challenge to the ban on gay marriage. Separately, gay-rights activists say they will try to get a measure on the ballot in 2016 to overturn the ban.
MISSISSIPPI: A ban was approved in 2004 with support from 86 percent of the voters, the highest percent among all the voter-approved bans in the U.S. There's no expectation it will be repealed except under a mandate from Congress or the U.S. Supreme Court.
MISSOURI: A ban was approved in 2004 with more than 70 percent support; there's been no effort to repeal it. The state Supreme Court is currently considering a legal challenge to a law that limits survivor benefits for deceased public safety officers to spouses who were in a "marriage between a man and a woman." The case was brought by the same-sex partner of a former Highway Patrol officer killed by a vehicle while investigating an accident.
MONTANA: Voters approved a ban in 2004; it's not under immediate threat. But gay-rights advocates believe that parts of the Supreme Court rulings could bolster their arguments in a case seeking domestic partnership recognition. In that lawsuit, gay couples are seeking inheritance, joint tax and other legal benefits.
NEBRASKA: Voters approved a constitutional gay-marriage ban in 2000. In light of the Supreme Court rulings, gay-rights activists are now looking at ways to challenge it. Doing so would likely require a citizen initiative and another statewide vote, though supporters aren't ruling out a lawsuit to challenge the amendment in federal court.
NEVADA: Although Nevada is among the 29 states with a constitutional ban, it also has a domestic partnership law providing extensive rights to same-sex couples. Legislators approved a resolution this year aimed at changing the constitution to allow same-sex marriage; it will need a second round of legislative approval in two years before going to a popular vote. Meanwhile, there's a case pending in federal court challenging the constitutionality of the ban.
NORTH CAROLINA: The most recent of the nation's gay-marriage bans was approved by North Carolina voters in May 2012. Gay-rights activists are looking at whether the Supreme Court rulings provide an opening to challenge it.
NORTH DAKOTA: A ban was approved by voters in 2004 with 73 percent support. The GOP-dominated Legislature also has voted repeatedly against gay-rights measures, including a bill in the last session to prohibit discrimination based on sexual orientation in housing, public services and the workplace.
OHIO: Voters approved a ban in November 2004 after an expensive ballot campaign that some analysts say boosted turnout among supporters of Republican President George W. Bush's re-election in the battleground state. The new Supreme Court rulings fueled the hopes of FreedomOhio, a coalition of gay marriage supporters that's working to overturn the ban in 2014.
OKLAHOMA: More than 75 percent of voters approved a gay-marriage ban in 2004. Repealing it would almost certainly have to be done through court challenges, since there appears to be little appetite in the Republican-led Legislature to embrace gay rights. Last session, the House voted 84-0 for a resolution to reaffirm marriage as a union between a man and a woman,
OREGON: Voters in this relatively liberal state approved a constitutional ban on same-sex marriage in 2004 with 57 percent support. It's now viewed as perhaps the most likely state to overturn such a ban; gay-rights activists and Democratic politicians are gearing up to place a repeal measure on the 2014 ballot.
SOUTH CAROLINA: In 2006, 78 percent of voters approved a constitutional ban. Little has changed since then. There were no bills introduced in the Legislature dealing with gay rights in 2013, and legislative leaders don't expect it to be an issue any time soon.
SOUTH DAKOTA: Gay marriage has been banned since the Legislature passed a law in 1996, and the prohibition was strengthened with a constitutional ban approved by voters in 2006. Activists say there are no current plans to ask voters to overturn it.
TENNESSEE: Voters approved a ban in 2006 with 81 percent support. It appears under no immediate threat.
TEXAS: Voters overwhelmingly approved a ban in 2005; there's been no organized drive to repeal it. However, gay-rights activism has increased in Texas in recent years, and Houston last year re-elected its openly lesbian mayor.
UTAH: Three same-sex couples have filed a legal challenge against Utah's gay-marriage ban, which was approved by voters in 2004. The case had been put on hold pending the Supreme Court rulings.
VIRGINIA: Voters approved a ban in 2006; it's unlikely that the Legislature dominated by conservative Republicans would take steps to repeal the ban. Gay-rights supporters haven't ruled out a lawsuit.
WISCONSIN: Voters approved a Republican-backed ban in 2006; repealing it would require votes in two consecutive legislative sessions, followed by a statewide referendum. In 2009, with Democrats in control, lawmakers passed statutes creating a domestic partner registry for same-sex couples. That registry is now under legal attack by a conservative group which argues that it violates the gay-marriage ban.
INDIANA: There's a state law prohibiting same-sex marriage but as yet no constitutional ban. Leaders of the Republican majority in the Legislature hope the Supreme Court rulings will provide motivation to get the ban passed so it can be put before voters in 2014. GOP Gov. Mike Pence says he supports a stronger ban.
PENNSYLVANIA: It's the only state in the Northeast that doesn't extend legal recognition to same-sex couples. An openly gay Democrat, state Rep. Brian Sims, plans to introduce a bill that would legalize same-sex marriage. It may not get far in the GOP-controlled Legislature, but it could be an issue in the 2014 gubernatorial campaign. Incumbent GOP Gov. Tom Corbett opposes gay marriage; the three Democratic challengers support it.
NEW MEXICO: Its statutes contain no law that specifically prohibits or legalizes same-sex marriage. Democratic Attorney General Gary King's office released a legal analysis in early June concluding that same-sex marriage is not authorized at this point. But lawyers for two gay men from Santa Fe are trying to expedite a lawsuit seeking a ruling that gay marriage is legal.
WEST VIRGINIA: Under a state law passed in 2000, West Virginia defines marriage as being between a man and a woman. The state does not have a constitutional ban, though some Republicans in the Legislature say they will intensify their push for one because of the Supreme Court rulings.
WYOMING: State law defines marriage as a civil contract between a man and a woman; there is no constitutional ban. Democratic state Rep. Cathy Connolly, a lesbian, pushed legislation earlier this year that would have permitted civil unions and banned discrimination against gays. Both bills died. She expects a proposal for legalizing gay marriage to be introduced by 2015; there's also the possibility of a lawsuit seeking marriage equality.