For more than half a century television has played a surprisingly important role in race relations in the United States. Had I been writing this 18 months ago, I might have said “the advance of race relations in the United States”, but these days I’m not so sure of the direction of travel.

In the mid-1970s a handful of liberal TV creatives persuaded the infamously cautious and socially conservative American networks into commissioning a string of sitcoms that sympathetically depicted black family life. Both The Jeffersons (1975-85) and Good Times (1974-79) were ratings hits, as to a lesser extent was Sanford and Son (1972-77) – a remake of the BBC’s Steptoe and Son, with an all-black cast transposed on to Watts, the poor black neighbourhood of Los Angeles.

For a moment American TV appeared to be edging ahead of wider society on the issue of race. Then, in 1977, came Roots – the story of a very different African American family.

Seven years before Roots was broadcast, political scientist Richard Scammon shocked the liberal wing of the Democratic party by describing the American electorate as being, for the most part, “unyoung, unpoor and unblack”. The same could have been said of the nation’s TV audience, and despite the successes of the earlier black sitcoms, the suits at ABC – the network behind Roots – convinced themselves that it was destined to be a flop. After all, the network had spent more than $6m on an eight-part mini-series that picked and prodded at slavery, the open sore of American history: the republic’s original sin.

In the weeks before broadcast the channel lost its nerve so spectacularly that executives embarked on a campaign of pre-emptive damage limitation. Roots was scheduled to run across eight consecutive nights – “stripping”, in TV speak. The hope was that if the series bombed, it would all be over before the critics would have time to sharpen their knives.

Why can’t we – one of the most diverse nations on earth – produce a comparable series?

What no one predicted in January 1977, when the series finally went to air, was that it would be a runaway success; a ratings and critical triumph on a scale unprecedented in TV history. About 100 million people, nearly half the population, tuned in to watch the final episode. Today only Super Bowls draw audiences like that. Presidential inaugurations – despite recent claims – are watched by far fewer people than saw Roots in 1977. The series can be seen as the 20th century’s cultural equivalent of Uncle Tom’s Cabin, a 19th-century bestseller – just without the stereotypes.

Roots came to Britain later the same year. Broadcast by the BBC, 19 million people tuned in to watch. I was not one of them. Deemed too young by my mother (quite rightly), I caught only brief glimpses of a handful of episodes – whenever the drama grew too violent I was hastily packed off to bed.

Yet despite this I knew all about the series because overnight the word Roots, and the names of the lead characters, Kunta Kinte and Chicken George, were added to the lexicon of racist chants and insults that were shouted at black people on the streets and black children in my school playground. The humanity of Alex Haley’s characters had little purchase on people who had long ago decided that black people were less than human. Indeed, the portrayal of black people in chains, abused and powerless, only encouraged their racism.

Alex Haley, the author of Roots, at a news conference in Utah, 1977 Photograph: Alamy

Perhaps things were better in other parts of the country but, paradoxically enough, in the north-east, where I grew up, Roots let loose a surge of racist harassment. So striking was this Roots effect that – as I discovered years later – the mother of one of the few other African children I knew at the time wrote to the BBC asking it to halt the broadcast, in the hope that such a move would stem the wave of racism that had engulfed her two boys. This was not what the makers of Roots had in mind when they set out to confront the realities of American slavery.

I finally got to watch Roots in my mid-teens, on a video rental. Slowly and meticulously Roots fed its black characters through the mincing machine of American slavery. People with names, hopes and family connections were destroyed and dehumanised before my eyes.

Many black Britons remember watching the 1977 broadcast of Roots with their families. They recall sitting on their sofas holding hands and weeping as Kunta Kinte, Kizzy Reynolds and Belle were subject to abuses that, in so many cases, had been visited upon their own ancestors. The only time I have heard of a similar phenomenon was three years ago, when black Britons went to the cinema as family groups, two or three generations all together, to watch 12 Years a Slave.

Roots means a lot to a lot of people, so when executives at the History Channel embarked upon a “reimagining” of the series, the stakes were high. The new Roots, currently showing on BBC4, has been a success both with audiences and critics. Better realised, more elegantly structured and far more lavishly filmed than the original, it manages to deliver as much emotional impact. It does this while staying true to the 1977 series in its graphic depictions of the violence upon which slavery and the slave trade relied.

The new series also benefits from an additional 40 years of academic research. The Gambia, from which Kunta Kinte is sold into slavery, is depicted as the sophisticated, globally aware, Islamic society that it was. And the revolt that he leads on board the slave ship, in the first, feature-length episode, carries the hallmarks of thorough research. Yet the viewing figures achieved by the original are beyond the reach of any series in today’s multichannel world, no matter how well made or cleverly scheduled.

What is also striking about the new Roots is that it makes clear that Kunta Kinte (played by British actor Malachi Kirby) and those around him are victims of British slavery. The ship on which they are transported is an English vessel; the union flag flutters prominently above the bridge. The Virginia in which Kinte is enslaved is a British colony. Which, of course, raises the obvious question: where is the British Roots?

Why can’t we – one of the most diverse nations on earth – produce a comparable series? Are there not enough epic, inter-weaving family sagas from the three centuries of Britain’s slave empire?

Of course there are. The records are in the archives, the names of those who grew rich on the backs of the slaves are methodically listed in the database of University College London’s Legacies of British Slave-Ownership project.

No one could suggest that we lack the writing or directorial talents needed to pull off such a series: and in Adrian Lester, Marianne Jean-Baptiste, Idris Elba, David Harewood, Sophie Okonedo, John Boyega, Naomie Harris, David Oyelowo, Thandie Newton, Hugh Quarshie, Chiwetel Ejiofor and others we have – for the first time – enough world-renowned black actors to play any and every conceivable role. All that is needed is courage and creativity.