Maine's new same-sex marriage law goes into effect on Dec. 29.
Gov. Paul LePage signed off on the election results on Nov. 29, and the law, passed by voters on Nov. 6, goes into effect 30 days after certification of the vote by the governor.
Voters in Maryland and Washington also approved laws on Nov. 6 legalizing same-sex marriage.
Representatives of the LGBT rights group Equality Maine said it's unclear exactly when gay couples will actually be able to exchange vows in Maine, since Dec. 29 falls on a Saturday and it's unknown if any municipal offices will be open that day to issue marriage licenses.
"This is the moment for which we fought so long and hard," said Betsy Smith, executive director of Equality Maine. "Through a devastating loss in 2009 and then three more years of countless phone calls, hours of walking door-to-door, endless data entry and an election night to be remembered for all time."
"For couples that have been waiting decades for the freedom to marry, waiting a few more weeks doesn't feel too long," said Jill Barkley, marriage project coordinator for the ACLU of Maine. "I can't think of a better way to welcome a New Year than having full equality for all loving and committed couples in our state."
Washington gay couples begin marrying this week, on Dec. 6.
The law takes effect in Maryland in January.
Gay marriage is already legal in New York, Connecticut, Iowa, Massachusetts, New Hampshire, Vermont and the District of Columbia.