"We stand disappointed, but not defeated," offered Rev. Nancy Petty with Pullen Memorial Baptist Church.
Unofficial returns showed the amendment passing with about 61 percent of the vote to 39 percent against.
Opponents vowed Wednesday to keep fighting.
"The only thing that has changed is that North Carolina has shamed itself by passing this constitutional amendment," offered Rev. Jimmy Creech of People of Faith Against Amendment One.
President Barack Obama's campaign said he's "disappointed" with the vote.
Obama campaign spokesman Cameron French said in a Tuesday statement that the ban on same-sex unions is "divisive and discriminatory." French says same-sex couples deserve the same rights and legal protections as straight couples.
That was not the view of supporters, who told ABC11 after the vote Tuesday that the amendment is needed to protect traditional marriage.
"We will place it in the safety of our constitution - keep it safe from judges and the legislature who might seek to redefine marriage for us," offered Rachel Lee with the pro-amendment group Vote FOR Marriage NC.
But opponents argue that the amendment is so broad that it also voids other types of domestic unions from carrying legal status. They warn that it could disrupt protection orders for unmarried couples.
"The voting majority has chosen discrimination and fear and inequality over the vision of our forefathers, that all are created equal," said Petty.
What the actual effect of the vote will be remains unclear. That's because North Carolina law already banned gay marriage.
"Same-sex marriage was illegal today; it's illegal tomorrow," said John Dinan, a political science professor at Wake Forest University who writes an annual review of state constitutional amendments in an interview with the Associated Press. "There were no same-sex civil unions recognized in North Carolina today. Those will not be recognized tomorrow. The bottom line is there's not a lot of change because of this amendment."
The amendment likely would affect issues other than gay marriage the most because the "marriage-plus" amendment prohibits not only same-sex marriage, but also same-sex civil unions. Nineteen states have such amendments, Dinan said.
For example, a handful of local governments provide benefits to employees who are involved in same-sex relationships. In Michigan, the state's highest court ruled that an amendment did affect those benefits, Dinan said. But in North Carolina, officials in Durham and Orange counties have said they don't expect to have to eliminate those benefits because of the amendment, he said.
Opponents had said they feared the law could affect domestic violence protections, some of which refer to people who live together. Dinan said he doubted that would happen, although Ohio had a three-year court fight over the issue before the Supreme Court ruled the laws weren't affected.
North Carolina is the 30th state to pass a constitutional amendment banning gay marriage. Six states -- all in the Northeast except Iowa -- and the District of Columbia allow same sex marriages. In addition, two other states have laws that are not yet in effect and may be subject to referendums.
Both sides said the hard-fought battle had brought new voters who will be active in other issues.
"I think we've built a huge coalition across North Carolina of people who believe godly values," said Tami Fitzgerald, head of Vote FOR Marriage NC. "And I believe that speaks well for people in our state who have somewhat been a silent majority in the past and I think you can expect them to be very active in the future, especially when they see the impact of their grassroots efforts."
But even the state House Speaker, who supported the amendment, expressed reservations about how long it would survive. Speaker Thom Tillis said he expects the amendment to be reversed within 20 years as today's young adults age.
While legislators can easily undo a state law, it's much harder to reverse a constitutional amendment, Dinan said. The latter requires a three-fifths vote in both legislative houses, then voter approval.
"One can't rule that out," he said. "But it's become more difficult to make that change now."
The fight will continue. On Wednesday, same-sex couples will ask for marriage licenses in Wilson and Durham, the start of a week-long campaign called "We Do" protesting their inability to wed.