The Washington, D.C. Council gave its final approval on Tuesday to recognize same-sex marriages performed in other states.
The council voted 12 to 1 to pass the legislation.
While the Human Rights Campaign, a lesbian, gay, bisexual and transgender rights organization, and other gay rights advocates applauded the vote, saying it was "simply the right thing to do," a group of traditional marriage advocates, including local ministers, were outraged.
"Every minister who fears God should be here," said Paul Trantham, according to The Washington Post. "This is disrespectful to the nation's capital. There is nothing equal about same-sex marriage."
Mayor Marion Barry casted the lone opposing vote. He initially voted with the rest of the council to approve the measure but after consulting with the religious community, he chose to stand with the ministers.
Last month, a group of primarily African American pastors and followers rallied in Freedom Plaza denouncing the D.C. Council's preliminary vote to recognize same-sex marriages conducted elsewhere.
Bishop Harry Jackson, Jr., of Hope Christian Church in Beltsville, Md., led the rally saying, "I'd rather be biblically courageous than politically correct."
While some passers-by were quick to call them protesters bigots, Jackson said the issue is not about gay rights.
"There's a difference between civil rights and sacred rights," he said. "Marriage has been defined by God."
"It's not about hating anybody or against anybody but we're just believing that we understand that society has always been founded on traditional marriage," Jackson proclaimed.
After Tuesday's vote, traditional marriage advocates offered a prayer outside the Wilson Building.
Jackson told The Washington Post that they are developing a "political and legal strategy" to protect traditional marriage.
The measure now heads to Congress for approval.
Massachusetts, Connecticut, Iowa and Vermont currently allow same-sex marriage. The Maine House, meanwhile, approved on Tuesday a bill that would make the state the fifth to legalize marriage for same-sex couples. The bill will go back to the Senate and House for a final vote.