Cornell Benjamin was beaten to death with a metal pipe while trying to stop rival street gangs from brawling outside a high school. It was December 1971, and Cornell, known as “Black Benjie”, was a top-ranking member of the Ghetto Brothers, one of the oldest street gangs in the South Bronx.

Back then, hundreds, possibly thousands, of mostly African American and Puerto Rican youngsters swore allegiance to neighbourhood gangs, knowns as “clubs”, distinguished by striking patches.

Cornell’s brutal murder fuelled gang tensions in New York City, which authorities feared would spark a wave of bloody retribution.

Instead, the 25-year-old’s death paved the way for an unprecedented peace treaty between the borough’s most notorious gangs, including the Savage Skulls, Black Spades and Seven Immortals.

The truce lasted a couple of years, and for a while Cornell was revered as a martyr who died trying to forge peace among the city’s black and Latino communities.

Now, almost 40 years after Cornell’s death, a grassroots campaign is under way to rescue his legacy, in the hope of inspiring youngsters and policymakers to recognise gang leaders as potential catalysts for change – not just criminals.

The Black Benjie Vive campaign, spearheaded by a social worker and a group of eighth-graders, wants the block where he died to be renamed in his honour.

“This guy was a peacemaker, a genuine Bronx hero who no-one knows, and we want to do something about that,” said Bonnie Massey, 39, a local middle school social worker who came across Benjamin in the 2015 Rubble Kings documentary.

“The Hoe Street peace treaty changed the course of history, that’s an inspiration for young people, and should be part of the narrative about who young brown and black people from the Bronx are and what they’re capable of. This is their story,” she added.

New York’s street gangs proliferated during the 1960s – a turbulent decade of economic and social decay, police brutality and leftwing political awakening.

By the late 1960s into the early 70s, the black and Latin power movements the Black Panthers and Young Lords regularly visited the Bronx to recruit members and hold meetings on social justice and political power.

As a result, the Ghetto Brothers became staunch Puerto Rican nationalists, and swapped turf wars for activism. They arbitrated beefs between rival gangs, with reformed drug addict Benjamin as chief mediator, and hosted street parties to promote unity between Latinos and blacks – a musical scene that many argue was the precursor to hip-hop.

But the multidimensional nature of gangs was disregarded after crack flooded American streets during the 1980s and 90s. The subsequent criminal justice crackdown targeted gangs – and entire black and Latino communities – amid warnings the epidemic could spread from communities of colour to white suburbs.

“Gangs were never just about crack and crime, they were complex people and structures who were also peacemakers invested in their communities, but suddenly all that history and struggle was deemed outdated,” said Dave Brotherton, a professor at the John Jay College of Criminal Justice and an expert in gang culture.

“Since then, racial stereotypes have been used to turn complex human beings into cardboard cutouts, and rationalize punitive forms of social control like mass incarceration.”

The campaign to pay tribute to Benjamin is an effort to reclaim the true complex history of the South Bronx gangs, according to Massey.

The students have canvassed local residents, started a petition, made a video to circulate on social networks, and pressed local officials – unsuccessfully so far – to authorize the change.

It’s unclear why the community board has not approved the change, as there is widespread support for honouring Benjamin, including respected old-timers like Lorine Padilla.

Padilla, 64, known as the first lady of the Savage Skulls, was married to Felipe “Blackie” Mercado – the gang’s founder and president. Back then, the Skulls was the biggest gang in the South Bronx, who brawled with rivals but also made efforts to drive out drug dealers operating in the area.

“We got politicized by the Black Panthers and Young Lords, who taught us to appreciate our culture and invest in our communities. We played a big role in the revitalization of the Bronx,” said Padilla, a retired social worker, standing on the spot where Benjamin was killed.”

Padilla was among dozens of gang members hired by Catholic priest Louis Gigante, founder of the South East Bronx Community Organization (Sebco) which spearheaded the area’s economic and civic rehabilitation.

“Of course we had some bad people in our gangs, but also very good people, and Black Benjie was one of them. He changed his life around while still living in the same circumstances, and died for something he strongly believed in, peace among his people. Our kids need these role models.” A documentary about Padilla’s life is out next year.

Brotherton added: “The constant moral panic against gangs has never stopped but history is messy, like daily life, and if we don’t learn from it we are doomed to repeat it rather than figuring out better ways to revitalize communities.”