Over the past year, both sides have courted the support of Washington's black community, a majority of the city's 600,000 residents and one traditionally perceived as opposed to same-sex marriage.

"In D.C., outreach to African-Americans wasn't part of the campaign. It was the campaign," said Michael Crawford, the leader of a pro-same-sex union group, D.C. For Marriage.

Crawford, who is black, said other residents weren't ignored, but his group and others weighed the city's racial makeup in planning their message. That made the debate here different than in other places that have considered gay marriage — places like California, where about 7 percent of residents are black, or Maine, where 1 percent are. Voters in both states struck down gay marriage laws.

In Washington, gay couples are expected to be able to apply for marriage licenses beginning Wednesday — but opponents are still challenging it in court.