Updated March 28 at 10:21 p.m.

Melvin King, a longtime community advocate, state legislator, and Boston’s first Black mayoral candidate to advance to a general election, has died at age 94.

His son Michael King confirmed Mel King’s death to GBH News Tuesday evening.

“He spoke truth to power, and he was pretty much beyond — above — reproach,” Michael King said. “That’s the openness and the example that he was trying to set. ‘It’s not that hard to do the right thing,’ is something that he would say.”

For the past half-century, King has been one of the city’s most well-known advocates for local communities of color. In politics, his endorsement was highly sought after by candidates seeking credibility with Boston’s Black community.

King was born in Boston’s South End neighborhood, which in the mid-20th century represented the heart of the city’s Black population. He graduated from what is now the John D. O’Bryant School of Mathematics and Science, then-Boston Tech.

King was first elected to public office in 1973 to the state Legislature representing Suffolk County. He lost to Ray Flynn in the 1983 mayoral election.

That run in 1983 would end up inspiring people like Tito Jackson, who ran for the office in 2017. He said he remembers being 8 years old, seeing a large Black man — in every sense of that word — speaking the truth. He said the Mel King way of organizing a coalition, across race and income, informed his own run.

“As sad of a moment as this is, it also means that Mel King lived an impactful life that touched the lives of tens of thousands — and maybe hundreds of thousands — of people,” Jackson said.

State Sen. Lydia Edwards, a frequent visitor to King’s Sunday brunches, said his passing marks the end of the city’s radically loving activists.

“I’m really sad because we don’t have any more Mels, not even a pipeline for Mels at all,” she said. “He was a universal uniter, above the geographic division, above class division, race — he was the one all organizers could look to and know his heart was the purest.”

King endorsed Edwards during her first, unsuccessful run for state Senate in 2016.

A young Black man sits behind his placard "Rep. M. King" in this black-and-white photo, listening while he leans on his hand next to a microphone.
Mel King, photographed in 1974. He had been elected to the state House of Representatives just one year before.
Bob Backoff/The Boston Globe via Getty Images Boston Globe

For Boston City Councilor Kendra Lara, King guided her political organizing from a young age.

As a state Representative, he helped the People Before Highways movement, a movement that put a stop to government attempts to extend the I-95 through Roxbury. Residents’ fierce pushback put 2,000 protesters on the street in 1969, which halted the development and ultimately led to the Orange Line being brought into those neighborhoods instead.

“When I learned that story — when I was in the sixth grade — is when I realized that people who looked like me and the people in my neighborhood had power. That if we could stop a 10-lane highway from cutting through our neighborhood, that there was absolutely nothing that we couldn’t do,” said Lara, who now represents Jamaica Plain and West Roxbury. “And Mel King is a part of that legacy.

“When I think about my community, it exists in the way it does because of him,” she continued. “And when I think about my generation of organizers — and when I think about the generation of Black and brown young people who grew up in movements, who grew up fighting to make sure that their community had a voice and power in what our neighborhoods looked like — it is because people like Mel King set the standard.”

“For decades, Mel King taught us all how to serve, how to build, and how to love,” Boston Mayor Michelle Wu said in a statement Tuesday night. “On behalf of the City of Boston, we send our deepest condolences to the King family and the many, many loved ones, mentees, and friends of Mel. With gratitude and determination to keep fighting, Rest in Power.”

“Mel King is an iconic figure for Boston, not just in the Black community, but Boston overall because he knew how to bring people together,” said Bishop William E. Dickerson II, a friend of King’s. “I know that his impact is going to be missed deeply by so many people, so many sectors, of our communities.”

Michael King, one of King’s six children, is the director of the South End Technology Center, which the elder King founded in 1997.

He says his father was part of the solution that helped pave the way to make Boston's leadership more diverse.

“You know, he was part of the solution to get us to be able to accept that any person who has done their homework and does their homework can reach any point in life,” he said.

King said he wanted to honor his father and rejoice in his life.

“I don’t think there’s anything to be sad about. We miss him, but that’s the selfish part of us, you know?” said Michael King. “I feel like I was blessed to be, you know — have a chance to, you know — be in this time, next to someone who took his journey so seriously.”

This story has been updated to include additional comments and information.

Mel King and contemporary politicians pose with a street sign: "Mel King Way."
Activist and former State Legislator Mel King, center, is honored by Boston Mayor Marty Walsh, left, who announced he would name a street after him during the annual Martin Luther King Jr. Memorial Breakfast in Boston on Jan. 16, 2017.
Jessica Rinaldi/The Boston Globe via Getty Images Getty Images