Voters in Washington state have now officially approved gay marriage, joining Maine and Maryland as the first states to pass same-sex marriage by popular vote, according to the AP and NBC News.

The final numbers on Referendum 74, which asked people to approve or reject a law legalizing same-sex marriage that state lawmakers passed earlier this year, showed just under 52 percent in favor and 48 percent against.

That measure was signed by Gov. Chris Gregoire, but it was on hold pending the outcome of Tuesday's election and has never taken effect.

The official result comes a day after opponents conceded defeat and two days after supporters of gay marriage declared victory, with initial returns having showed the measure leading by a margin similar to the final numbers.

Washington was just one of four states where voters had a say on gay marriage this election year. Maryland and Maine voters approved gay marriage Tuesday night, while voters in Minnesota turned down a proposed constitutional amendment that would have banned same-sex marriage.

Six other states -- New York, Connecticut, Iowa, Massachusetts, New Hampshire, Vermont -- and Washington, D.C., already allow gay marriage. But Maryland, Maine and Washington are the first to enact it by public vote.