At the Democratic National Convention on July 28, activist and former White House intern Sarah McBride became the first openly transgender person to speak at a national party convention. (Video: The Washington Post; Photo: Ricky Carioti/The Washington Post)

On Thursday, Human Rights Campaign national press secretary Sarah McBride became the first transgender American to address a major party convention — and moved delegates to their feet by recounting how her late husband had fought for LGBT rights even as he was dying from cancer.

"I met Andy, who was a transgender man, fighting for equality, and we fell in love," she described, as the audience applauded. "And yet even in the face of his terminal illness, this 28-year-old, he never wavered in his commitment to our cause and his belief that this country can change. We married in 2014, and just four days after our wedding, he passed away."

"Will we be a nation where there’s only one way to love, one way to look, one way to live?" she asked. "Or will we be a nation where everyone has the freedom to live openly and equally?"

McBride's speech, which lasted less than four minutes, told only a small fraction of her story. McBride, one of the first openly transgender people to work in the White House, helped influence the administration's policy on transgender rights and shared her stories with some of its most influential figures.

Former White House intern Sarah McBride, who came out as a transgender woman during her senior year in college, discusses the Obama administration's legacy on LGBT issues. (Jorge Ribas/The Washington Post)

A Delaware native, McBride worked on Beau Biden's two campaigns to serve as the state's attorney general. She came out in 2012 just after stepping down as student body president at American University, she recalled in an interview last year, even though she was terrified that she "would be a disappointment to the people who had invited me into their lives, into their careers."

But shortly after she posted the news on Facebook, Beau Biden called her to offer his support.

"This is Beau," McBride recalled the vice president's son, who died in 2015, as saying. "Hallie and I are so proud of you. We love you, and you’re still part of the Biden family."

Before she came out, McBride had applied to the White House for an internship — using the name Sarah and explaining she was transgender. She was hired in the Office of Public Engagement and started there in August of 2012.

While she was there, she spoke openly with some of her colleagues about her experience.

"There's no question that the best way to get people to care about an issue is to humanize it," she said. "It was easier to forget, or be dismissive about, transgender issues when there weren’t transgender staffers or interns  walking the halls of the White House."

During an inaugural celebration in January 2013 at the vice president's residence, McBride and her mother were lining up for a picture when Biden wrapped his arm around her.

"Hey, kid, are you happy?" the vice president asked.

"Yeah," she replied.

"I am so happy you're happy," he replied. "And I just want to let you know that Beau is so proud of you, Jill is so proud of you and I'm so proud of you. And I'm so happy that you're who you are."

McBride's husband died in 2014, and several months later, she returned to the White House to attend its annual LGBT reception. While walking through the reception, she ran into White House senior adviser Valerie Jarrett, her former boss. While Jarrett had written her after her husband's death, McBride didn't know if she would remember her by sight.

"She gave me a hug," McBride recalled, "and said, 'Welcome home.' "