It’s a familiar story: a young director heads to the Sundance film festival with their debut feature. The crowd is wowed; jury likewise. The movie gets picked up for a major distribution deal and is deemed an instant classic. But while the likes of Quentin Tarantino, Steven Soderbergh, Robert Rodriguez, Richard Linklater, Darren Aronofsky, Paul Thomas Anderson, Wes Anderson and the Coen brothers have converted Park City acclaim into enduring careers, even Oscars, things turned out rather differently for Leslie Harris.

I meet Harris, now 57, for tea at the Trade Union Cafe in Brooklyn, not far from the home she shares with her husband, a New York Times photographer. Soft-spoken and gentle, she was born in Cleveland, Ohio. She loved cinema from an early age and, spurred on by her touring-musician father and a mother big on female empowerment, moved to New York to pursue a career in advertising, before jacking it in to shoot her first movie.

Its $130,000 budget came from a day job temping, night work at a non-profit film organisation that provided equipment in exchange for time, occasional gigs directing commercials for beauty salons in her neighbourhood – and, when cash dried up in post-production, cheques from the author Terry McMillan and the film-maker Michael Moore.

Just Another Girl on the IRT (1993) is the moving and exuberant story of Chantel (Ariyan A Johnson), an outspoken 17-year-old black girl, a top-grade student slated to graduate from her Brooklyn high school a year early, her eyes set on a career in medicine. The film’s poster was one of the first to feature a young black girl solo; its tagline was: “If you think you know her, think again.”

Harris had already had a lifetime of being prejudged and underestimated; Chantel was an expression of her desire to prove people wrong. “I would see these young girls getting on the train after school and they would be so loud, people would go to the next car,” she says. “There was a stereotype that people had. I wanted to follow these young people home, to see what they were really about.” It wasn’t just the women who got stereotyped: when she pitched the script to studios, they wanted Harris to make Chantel’s boyfriend a drug-dealer; she refused.

Chantel breaks the fourth wall in the film, telling us how she seeks not to be defined by her background, or by the personal challenges that threaten to overcome her. But the real story is how her intelligence is often taken for granted by the people in her life, particularly men, black and white alike, who see her as a mouth to be silenced, rather than a mind to be cultivated.

“[Not] just another movie,” raved Rolling Stone’s critic at the time. “Harris offers an adrenaline rush of energy and talent. Her artfully stylised, explosively funny film also manages to be deeply moving without jerking easy tears.”

The film stormed Sundance, taking home the special jury prize and attracting the attention of Miramax, with whom she brokered the first ever wide-release deal for a film directed by an African American woman. It hit more than 200 screens in the US and travelled to 20 countries beyond. Harris was lauded as a game-changer. And then … nothing. Twenty-five years on, Harris has yet to make a second movie – just like Julie Dash, another black female director, whose debut film, Daughters of the Dust, took top honours at Sundance two years before.

What happened? “I had scripts right out the bat after Just Another Girl,” says Harris. “Which I thought were interesting: people loved them. And my agent said,: ‘Well, I can’t get them funded. We can’t get a film financed with a black woman lead.’”

The problem, thinks Harris, was always to do more with gender than race, both in front of the camera and behind. Back then, black people were making movies, but they were all men: Spike Lee, John Singleton, Ernest Dickinson. “If you look back at the 90s, it was really a boys’ club – Boyz in the Hood, Juice, Straight Out of Brooklyn, Hanging With the Homeboys. There were very few women who were getting that attention. Hollywood was embracing black males.

“The difference for me is that they didn’t really want to tell stories about black women, and they surely didn’t want to have a black woman behind the camera.” She even had one such director tell her that she was “in the way”– taking up a valued token spot that should have gone to him.

Harris has mostly spent the past quarter-century teaching, at colleges across the US and as a professor at New York University Tisch School of the Arts. Some screen work has come her way: she made a short for Showtime about Bessie Coleman, the first African-American pilot, which she struggled to turn into a feature. At the moment, she is still trying to get funding – as she has for the past five years – for a second movie, I Love Cinema, a sexual satire about a sophisticated and outspoken academic called Layla who becomes involved in a cinema-inspired racial controversy (Layla is evidently something of a spiritual relation to Chantel – and, indeed, to their creator). One Kickstarter attempt in 2013 ended up with just $4,074 of its $35,000 goal.

The climate today may be different, yet the fact remains that 93% of the biggest US movies are directed by men, and that between 2007 and 2016, 80% of all female directors made just one film. For female directors of colour, that percentage is 83.3%. Still, Harris remains upbeat. She namechecks Dee Rees and Ava Du Vernay as evidence of real industry progress, and a new generation of viewers are discovering her film on streaming services such as Brown Sugar.

Aspiring black female directors may be concerned by her example, but at least, she says, she has retained her integrity. “I made the film I wanted to make,” she smiles. “Never give up. I’m the perfect example, after 25 years. Tides change. The climate changes. Never compromise too much of your story.”

Leslie Harris will attend screenings of Just Another Girl on the IRT at the Cinema Rediscovered festival at the BFI Southbank, London, on 27 July and Watershed, Bristol, on 28 July