Miami (CNN) Victory Fund, a political action committee whose sole aim is electing LGBTQ politicians to office, endorsed South Bend, Indiana, Mayor Pete Buttigieg on Friday in New York, validating the mayor's rise from small-city mayor who was not out when he was first elected to an upstart presidential candidate to a gay political icon.

The endorsement of the first top tier LGBTQ presidential candidate comes on the 50th anniversary of the Stonewall Uprising , a seminal moment in the LGBTQ movement where members of the gay community rioted against mistreatment at the hands of the police.

In an emotional event that doubled as a belated birthday celebration for the mayor's husband, Chasten, the candidate opened up about his coming out and marriage. His remarks centered heavily on the progress the LGBTQ community has made since Stonewall.

"We haven't seen equality come to the land, not by a long shot, but think about what it means that 50 years after Stonewall, we could be gathered in a room with a top tier candidate for the American presidency and be in a room with his husband," Buttigieg said to cheers.

Annise Parker, the head of Victory Fund and a former mayor of Houston who was one of the first gay mayors of a major US city when she was elected in 2010, opened the event and announced the endorsement, telling the audience of primarily white, gay men that Buttigieg is "redefining what is possible in American politics and LGBTQ Victory Fund is ready to stand with him."

Parker called the mayor's candidacy "revolutionary ... not just transformative" for the LGBTQ community.

"Who here thinks tonight, on the 50th anniversary of the Stonewall Uprising, we should go one step further?" Parker said. "This moment is important for our community, but this moment is important for our country. America needs us to step up, just as it needs Mayor Pete to step forward. Mayor Pete's progress is our progress, his journey is our journey."

Buttigieg seemed more at ease at the event than at more traditional campaign events, hugging Parker after the endorsement was announced. Chasten joined the candidate onstage, too, and helped people ask questions by picking written questions from the audience out of a bowl, including which one of the two proposed marriage and whether the mayor's style had improved when they started dating.

"Well, my socks match, so that is progress," Buttigieg joked, adding that Chasten sometimes "threatens to take away my gay membership card" because of his style.

Buttigieg's candidacy, especially early in his campaign, benefited from considerable support from gay activists and donors, many of whom helped fill his campaign coffers before he caught momentum. Victory Fund's endorsement comes a day after the mayor used his closing statement in the first Democratic primary debate to say his marriage exists only because of one vote on the Supreme Court.

"By the way, anyone catch the debate last night?" Buttigieg said to cheers. "How did I do?"

Parker, in an interview before the event, touted the historic nature of Buttigieg's candidacy.

"Victory Fund has a singular mission and that is to help LGBT people succeed in the political process," Parker said. "He is what we work for. He is the embodiment of the mission."

The endorsement is the first time Victory Fund has endorsed a presidential candidate.

Parker noted, however, that the organization did not get behind Buttigieg until he showed some viability in the presidential race.

Parker said she told Buttigieg in a private conversation that he needed to "go out and compete" and "do your absolute best" before the group got behind him.

"We have watched him thus far in the race and we believe that he has earned our endorsement just as he has earned the support of hundreds of thousands of Americans all across the country," Parker said. "He is a capable, competent, experienced leader, ready to move up in politics."

Buttigieg, at the age of 33, came out in a 2015 essay in the South Bend Tribune, in which he nodded to the fact that the Supreme Court would soon decide on whether same-sex marriage was legal nationally by writing that he thought his public coming out "could do some good" for people struggling with their sexuality.

"It took me a while to come out, a long while, even to myself, it was a long road of self-awareness and struggle and denial," Buttigieg told an audience in Iowa in June. "Even after I did come out to myself and started to tell friends and was elected mayor of my hometown, it was easy to drag my feet about telling anyone else."

Buttigieg's rise from small-city mayor to standout presidential candidate has turned him into a gay icon, a position that even the mayor has said was unlikely for him just a few years ago.

"It's a huge factor," James Olearchik, a 42-year-old educator from Brooklyn, said about the mayor's sexuality on Friday. "It is a real moment for our community to sort of take the national stage in a way that says, yes, he is a gay candidate but there is a lot more to him. And I want to make sure I am supporting that and supporting my community."

Buttigieg wrote in his 2019 campaign memoir that, when he came out later in life, he didn't want to become "a poster child for LGBT issues." And in speeches to LGBTQ groups on the campaign trail -- including in an emotional address at the Victory Fund National Champagne Brunch in Washington earlier this year -- Buttigieg said, "If you had shown me exactly what it was that made me gay, I would have cut it out with a knife."

"Thank God there was no knife," he added.

Other LGBTQ lawmakers, like former Rep. Barney Frank, have watched Buttigieg's rise with astonishment, bewildered by the fact that a gay politician would reach such heights.

"It's a sign of enormous progress," said Frank, who married his longtime partner, James Ready in 2012, making him the first gay politician to be married in office. "I would have told you three or four years ago, a gay candidate will be OK, but I didn't think it will be an asset."

"It keeps moving quicker," Frank added, cognizant that then-Sen. Barack Obama did not favor same-sex marriage during his 2008 run and only backed marriage equality in 2012, a mere seven years ago.

Parker said Buttigieg's candidacy, in and of itself, is groundbreaking.

"Every day Pete Buttigieg is part of this amazing campaign, he sets new standards and he breaks new ground," she said.

But it's also the unsaid moments -- like when Buttigieg announced his campaign and was embraced onstage by his husband, Chasten -- that reverberate beyond the LGBTQ community and normalize gay marriages for many Americans who may not seem gay couples on a regular basis, Parker said.

"It is even more powerful when he stands up, hand in hand with his husband, and that image is beamed into American households all across America," said Parker. "He is opening up who we are as LGBTQ people, he is changing the image of who we are, and he is broadening our representation."

The couple closed the event by asking each other what made them smile today. Buttigieg said the crowd, but Chasten asked the audience to raise their hands if they had ever felt singled out or ostracized. Nearly everyone raised their hands.

Chasten then asked who would be willing to help a person who felt that way and every hand shot up, leading the mayor's husband to say that is what makes him smile every day.

Buttigieg smiled, turned to the audience and said, "Did I marry up or what?"