The vote is considered the first step toward eventually allowing gay marriages to be performed in Washington. Congress, which has final say over the city's laws, will get 30 days to review the bill assuming Democratic Mayor Adrian Fenty, a supporter, signs it. If Congress takes no action, the bill will become law automatically. President Barack Obama and congressional leaders have not signaled where they stand.
"The march towards equality is coming to this country, and you can either be a part of it or stand in the way," said David Catania, one of two openly gay D.C. Council members.
Vermont, Connecticut, Massachusetts and Iowa already allow gay marriage and lawmakers in several other states are considering whether to do the same. New York recognizes gay marriages performed in other states.
The D.C. Council vote was 12-to-1, with former Mayor Marion Barry casting the lone opposing vote. He called it an "agonizing and difficult decision" that he made after prayer and consulting with the religious community.
Catania called the issue one of fundamental fairness and said it's about acknowledging that his family is just as valid as anybody else's.
The congressional review could be the new Congress' first opportunity to signal its appetite for re-examining the Defense of Marriage Act, which bars federal recognition of same-sex marriages and allows states to do the same.
Advocates from both sides were part of an overflow crowd that filled city hall, and more than 100 opponents from churches in the Washington region held a rally across the street on Freedom Plaza. Among them was the Rev. Derek McCoy from the Hope Christian Church in Beltsville, Md.
"Once you redefine marriage, you redefine family," he said.
Gay marriage supporters gathered outside the council hearing room included Ed Grandis, a lawyer who lives in Dupont Circle with his husband, J.D. Campos. The pair married in California last year during the time same-sex marriage was legal there, and they hope to have their marriage recognized in D.C.
"We don't have any interest in making their religious institution recognize our marriage or our relationship," Grandis said. Instead, Grandis said, it's about the government recognizing the couple's civil rights.
The district already recognizes domestic partnerships, but gay marriage supporters say that's not enough.
"It's an equality issue," said Sara Mindel, who has been with her partner for nine years and has a 10-month-old son. "In my mind, marriage, although it's a wonderful religious ceremony, ultimately gives you so many important states rights and legal rights."