While most of the attention was on the results of the presidential elections on Wednesday, there were important gains for the rights of same sex couples after four states voted in favor of same-sex marriage.
Voters in Maryland, Maine and Washington approved marriage equality in referendums run in parallel with Tuesday's elections -- the first time it has ever been approved at the ballot box in the United States.
Those in Minnesota, meanwhile, rejected a proposal to ban gay marriage in the northern state's constitution.
"It's a proud day to be proudly out," said Zack Ford, editor of the LGBT section of ThinkProgress.org, a political blog affiliated with the liberal Center for American Progress think tank.
"The momentum for marriage equality has never been stronger," added Chad Griffin, president of the Human Rights Campaign, the nation's largest lesbian, gay, bisexual and transgender civil rights organization.
"With poll after poll showing a growing majority of support, we have a renewed certainty that we will win this fight."
Same-sex marriage is legal in Connecticut, Iowa, Massachusetts, New Hampshire, New York and Vermont, as well as the District of Columbia.
But it remains a divisive issue, banned in some 30 of the 50 states -- notably California, where its legalization was overturned in a 2008 referendum -- and fiercely opposed by evangelical Christians and Roman Catholic bishops.
It is also not recognized at the federal level, with the Defense of Marriage Act (DOMA) denying married LGBT couples the same tax and social security benefits as their straight counterparts.
Obama made history as the first serving president to publicly support marriage equality, while the Supreme Court is to consider later this month whether to rule on DOMA's constitutionality.
"There is no doubt that we will continue to see tremendous strides forward like we've made during his first four years with our 'ally-in-chief' back in office," Griffin said.
His defeated Republican rival Mitt Romney held to the social-conservative position that marriage can only exist between a man and a woman -- a stance that plays strongest in the American heartland.
Across the Atlantic, France's Socialist government adopted a draft law Wednesday to authorize same-sex marriage and adoption, despite Roman Catholic and right-wing opposition.
Tuesday also saw the election of Tammy Baldwin of Wisconsin as the first openly gay member of the US Senate. Since 1999 the Democrat has been a member of the lower House of Representatives.
"I didn't run to make history, I ran to make a difference," Baldwin told supporters in the state capital Madison after trouncing former Republican state governor and federal health secretary Tommy Thompson.
Support for marriage equality has been growing slowly but steadily among Americans, with an August 2010 opinion poll for CNN television becoming the first of several indicating majority support.
"We believe that in a few years, gay marriage will cease to be seen as strange by anyone," said Joseph McClane, 62, a resident of Rockville, Maryland who has been with his partner Bill Nickel for 18 years.