Same-sex couple Douglas Robinson, right, and Michael Elsasser exchange wedding rings during their July 2011 wedding ceremony at the City Clerk's Office in New York. (Shannon Stapleton / AP)
Same-sex marriage became a reality in the United States in 2004 in the wake of a ruling by the Massachusetts Supreme Court. Prior to 2012, same-sex marriage was also legalized in New York, Connecticut, Iowa, New Hampshire, Vermont and Washington, D.C.
Early in 2012, Washington State and Maryland both approved same-sex marriage laws, but neither took effect immediately and both were expected to be challenged in referendums.
In May 2012, President Obama declared that he supports same-sex marriage, and there are currently a number of cases involving gay marriage in federal courts. - The New York Times, msnbc.com