Then, nine days after that, Dianne Feinstein, then the president of the Board of Supervisors, announced to the world that Milk and San Francisco Mayor George Moscone had been gunned down in City Hall by former Supervisor Dan White.

"I remember this so well, and it's still traumatic," Feinstein, now a U.S. senator, recently said on KQED's Political Breakdown.

She vividly recalls the day she found Milk's body. "Because I tried to get a pulse in his wrist and put my finger in a bullet hole," she said. "And it was clear he was dead. And that changed the world."

'He Wanted to Open the City Up to Everyone'

Moscone had been elected mayor three years earlier, earning a tough, narrow victory over John Barbagelata, a very conservative opponent who represented old San Francisco.

"Moscone was a charmer," said filmmaker Steve Talbot. "He was an extremely handsome guy. Everybody said he had a movie star smile. He loved people. They called him the people's mayor when he got into office, and everyone called him 'George.' "

Talbot wrote a new PBS documentary titled "Moscone: A Legacy of Change" that is airing on KQED this month.

Remembering George Moscone, 'The People's Mayor' of San Francisco Often overshadowed by Harvey Milk in death, George Moscone left behind a lasting progressive legacy as a state legislator and mayor.

"I think that was a watershed election in the history of San Francisco," Talbot said. "It really changed things because the old establishment in San Francisco, which was essentially white Italian and Irish guys, gave way to this new guy who is also white Italian. But he wanted to open the city up to everybody. The full rainbow of San Francisco people, including Harvey Milk, who he appointed to his first commission."

Back then, the San Francisco we know today was just beginning to emerge. Art Agnos, who became mayor more than a decade later, says Moscone opened up city government.

"For the first time, neighborhood activists in large proportions were put on commissions by Mayor Moscone, and that signaled a kind of new engagement by neighborhoods that we hadn't seen in San Francisco before," Agnos said.

'What We Were Doing Was Brand-New'

Thousands of gay men and lesbians were flocking to the city at the time -- some rejected by their families, others just wanting a place to be themselves. Many gravitated to the city's Castro District, where Milk, then just a colorful neighborhood activist, owned a camera store.

At the time, Cleve Jones was in his early 20s and drawn to Milk's brand of populism.

"It's just a wonderful thing when one is allowed to participate in something that is brand-new," Jones recalled recently. "And we all knew that what we were doing was brand-new. Nobody had ever seen this before.

Milk's rise also attracted people like Gwenn Craig to get involved in his campaign for gay rights.

"It was amazing the number of people we had volunteering on his campaign and the number of people who saw him as the best hope for how we were going to succeed as a movement," Craig said.

In 1977, when Milk won a seat on the San Francisco Board of Supervisors, Craig said there were a lot of tears.

"People were so swept up because to them it meant not just Harvey's acceptance by the voters of San Francisco, but also their acceptance by society," she said.

Death at City Hall

But the celebration in San Francisco was short-lived. On Nov. 27, 1978, less than two weeks after the Jonestown massacre, former Supervisor Dan White climbed through a basement window at City Hall carrying a loaded gun and headed for the mayor's office.

White had suddenly resigned from the board and went into a rage after learning that Mayor Moscone would not reappoint him. After shooting Moscone, White walked across City Hall and shot and killed Milk.

Cleve Jones, then a student intern working for Milk, got the news while he was on Castro Street that day. He raced back to City Hall and up to Milk's office.

"I went running up the stairs to find Harvey and saw his body when I turned the corner," Jones said. "It was just horrifying. I'd never seen a dead person before."

Devastated, Jones organized a candlelight march that night from the Castro down Market Street.

"I just thought 'Well, it's all over now.' But then the sun went down and people began to gather, and they were gay and straight and young and old and black and brown and white, and we marched to Civic Center and filled it with candlelight," he said. "And I remember standing in that huge crowd and realizing that of course it wasn't over. It was, in fact, just beginning."

LGBT Representation 40 Years After Milk

Since Milk, the gay rights movement has scored political victories that would have been inconceivable four decades ago. Today, Milk's seat on the Board of Supervisors is occupied by another openly gay supervisor, Rafael Mandelman.

"As someone who was 5 years old when he was shot, I am continually grateful not just for Harvey but for the folks of that generation who really did change the world," Mandelman said.

Why Harvey Milk Still Matters to These Young People A lot has changed in the LGBT world in the last 40 years. How much do young queer people today know about Harvey Milk? And what does he mean to them?

But first, Mandelman notes, Milk changed himself. The closeted former Wall Street stockbroker left New York and came to San Francisco, where he could open a small business and be out.

"Today, young queer professionals certainly can be in San Francisco and be out and proud and work at Salesforce or in real estate or banks or any aspect of American business and do just fine," he said.

Mandelman is hoping to build on Milk's legacy of progressive politics, but he worries that as queer people are priced out of gay neighborhoods like the Castro, it dilutes their political power.

"You know, I am the only LGBT person on the Board of Supervisors, and that is less representation than our community has had in decades. That's a little concerning to me," he said.

But there is much more LGBT representation where it would have been hard to imagine four decades ago, in places like rural Minnesota, Kansas and Arizona, where voters elected LGBT officials earlier this month.

Gwenn Craig, who came to San Francisco in the 1970s and worked with Milk before he was killed, traces it all back to Milk pushing people to come out of the closet.

"I do think that he sort of started this path that made it possible for the openly gay officials that were elected in this last round. And it makes me so proud," Craig said.