What the U.S. looked like the day of the Supreme Court nationwide marriage-equality ruling
In the United States, same-sex marriage is legal in Massachusetts (2004), California (2008 for four months, then 2013 for good), Connecticut (2008), Vermont (2009), Iowa (2009), New Hampshire (2010), Washington, D.C. (2010), New York (2011), Maine (2012), Maryland (2012), Washington (2012), Delaware (2013), Rhode Island (2013), Minnesota (2013), New Jersey (2013), Hawaii (2013), New Mexico (2013), Oregon (2014), Pennsylvania (2014), Illinois (2014), Colorado (Oct. 6, 2014), Indiana (Oct. 6, 2014), Oklahoma (Oct. 6, 2014), Utah (Oct. 6, 2014), Virginia (Oct. 6, 2014), Wisconsin (Oct. 6, 2014), West Virginia (Oct. 9, 2014), Nevada (Oct. 9, 2014), North Carolina (Oct. 10, 2014), Idaho (Oct. 15, 2014), Arizona (Oct. 17, 2014), Alaska (Oct. 17, 2014), Wyoming (Oct. 21, 2014), Kansas (Nov. 12, 2014), Montana (Nov. 19, 2014), South Carolina (Nov. 20, 2014), Florida (Jan. 6, 2015), Alabama (Feb. 9, 2015) and Guam (June 8, 2015). It also is legal in the independent city of St. Louis, Missouri (Nov. 5, 2014), the separate county of St. Louis (Nov. 5, 2014) and Jackson County, Missouri, which includes Kansas City and Independence (Nov. 7, 2014). That's 37 states, one territory (there are five), the District of Columbia, and three of Missouri's four largest cities.
(At the moment, same-sex marriage is paused in Alabama due to conflicting rulings from federal courts and the Alabama Supreme Court. Litigation is ongoing. In Kansas, same-sex marriage is not yet happening in all counties, and the state continues to refuse to recognize its own marriages. Litigation is ongoing.)
What's the deal in Missouri? Since Oct. 6, 2014, when Attorney General Chris Koster opted not to appeal a marriage-recognition ruling from a state court in Kansas City, Missouri has recognized same-sex marriages from anywhere in the world. Then, on Nov. 5, 2014, a state judge in St. Louis struck down Missouri's marriage ban and weddings began in St. Louis and St. Louis County (the city of St. Louis is independent and not located in any county). Koster appealed the decision but did not seek a stay to stop the St. Louis marriages. Then, on Nov. 7, a federal judge in Kansas City struck down the state's ban and marriages began in Jackson County. Koster appealed that ruling as well. The U.S. Court of Appeals for the 8th Circuit refused to lift a stay that prevents the ruling from having statewide effect. Oral arguments in that appeal were to take place May 12 in Omaha but on April 29 the court canceled them in anticipation of the U.S. Supreme Court's expected nationwide marriage ruling in June.
Bans on same-sex marriage in Arkansas, Louisiana, Mississippi, Nebraska, South Dakota and Texas have been struck down by federal or state courts, but the rulings were stayed for appeal. In Louisiana and Puerto Rico (another of the United States' five inhabited territories), federal courts upheld bans. The rulings were appealed. (On March 20, 2015, Puerto Rico's government reversed course and invited the U.S. Court of Appeals for the 1st Circuit in Boston to strike down its ban.) Oral arguments in cases from Louisiana, Mississippi and Texas took place before the U.S. Court of Appeals for the 5th Circuit in New Orleans on Jan. 9. Journalists exiting the courthouse said they expected a 2-1 ruling in favor of same-sex marriage. Oral arguments in cases from Arkansas, Missouri, Nebraska and South Dakota were scheduled to take place May 12 before the U.S. Court of Appeals for the 8th Circuit in Omaha until the court canceled them on April 29 in anticipation of SCOTUS' June nationwide marriage ruling.
(The six states not yet mentioned: Bans in Kentucky, Michigan, Ohio and Tennessee were upheld by the U.S. Court of Appeals for the 6th Circuit in Cincinnati. These are the four cases that went to the U.S. Supreme Court and that are expected to result in a ruling for nationwide marriage equality this month. North Dakota was sued twice but the U.S. district court paused the cases to wait for SCOTUS. Georgia also was sued, but there has been no movement in the case lately.)
As for the other three inhabited U.S. territories: The Northern Mariana Islands (population 54,000) are required to let same-sex couples marry due to binding precedent in the 9th Circuit. However, no couple has sought to marry. There also have been no same-sex-marriage moves in the U.S. Virgin Islands (population 105,000), which are in the 3rd Circuit (where all states have same-sex marriage but achieved it in ways that did not involve a circuit-appeals-court ruling). American Samoa (population 55,000) has a unique legal situation. Lambda Legal recently tried to explain it here.
Indian tribes: Same-sex marriage also has been explicitly legalized within the Coquille Indian Tribe in Oregon (2009), The Suquamish Tribe in Washington (2011), the Little Traverse Bay Bands of Odawa Indians in Michigan (2013), The Confederated Tribes of the Colville Reservation in Washington (2013), the Pokagon Band of Potawatomi Indians in Michigan (2013), the Iipay Nation of Santa Ysabel in California (2013), the Cheyenne and Arapaho Tribes in Oklahoma (2013), the Leech Lake Band of Ojibwe in Minnesota (2013), the Puyallup Tribe of Indians in Washington (2014), the Tlingit and Haida Indian Tribes in Alaska (2015), the Oneida Tribe in Wisconsin (2015), and the Keweenaw Bay Indian Community in Michigan (2015).
Historical notes: In Utah, 1,259 same-sex couples married between Dec. 20, 2013, and Jan. 6, 2014, when the U.S. Supreme Court stayed a Salt Lake City federal judge's strikedown of the state's gay-marriage ban. The stay was lifted Oct. 6, 2014, when the U.S. Supreme Court declined to review pro-same-sex-marriage rulings from appeals courts in three federal circuits. In Michigan, 315 same-sex couples married in four counties on Saturday, March 22, 2014, before the U.S. Court of Appeals for the 6th Circuit issued a stay. In Arkansas, 541 same-sex couples received marriage licenses before the Arkansas Supreme Court issued a stay a week after the May 9, 2014, strikedown. In Wisconsin, more than 500 same-sex couples married June 6-13, 2014, before a federal judge finalized her paperwork and issued a stay -- which was lifted by the U.S. Supreme Court action on Oct. 6, 2014. In Indiana, some 800 same-sex couples married June 25-27, 2014, before the U.S. Court of Appeals for the 7th Circuit issued a stay -- which was lifted by the U.S. Supreme Court action on Oct. 6, 2014. In Colorado, more than 300 same-sex couples married in Boulder, Denver and Pueblo counties in June and July 2014 after various legal developments, including the state's marriage ban being struck down in both state and federal court. The counties eventually were forced to stop issuing gay licenses by the state Supreme Court and Attorney General John Suthers, with Boulder being the final county shut down on July 29, 2014. Colorado resumed issuing marriage licenses to same-sex couples on Oct. 6, 2014, following the U.S. Supreme Court rejection of appeals from other states located in the 10th Circuit.
In U.S. states that do not allow or recognize same-sex marriage, married same-sex couples who live there are still recognized as married for many federal purposes, including income tax, immigration, military benefits and other matters that always have been tied to whether a couple entered into a legal marriage anywhere in the world rather than to a state's marriage rules.