Washington DC city council has voted to recognise same-sex marriages conducted in other US states.
Because Washington DC is not a state, the decision will now have to be approved by Congress before it can become law.
Four US states - Vermont, Connecticut, Massachusetts and Iowa - now permit gay marriage, and legislation to allow it is in progress in other states.
The resolution was passed in the council by 12 votes to one.
Council member David A Catania - one of two openly gay members of the body - explained his reasons for supporting the measure during the debate.
"This issue is whether or not our colleagues on a personal level view me and [Council member] Jim Graham as your equals," he said.
"If we are permitted the same rights and responsibilities and obligations as our colleagues. So this is personal. This is acknowledging our families as much as we acknowledge you."
Fellow council member, and former Washington DC Mayor Marion Barry, was the only member to vote against the proposal.