In October 1927, the circus came to Roanoke, Virginia. It was a vast affair. There were four locomotives, 100 railcars, 1,600 people, five rings, six stages, elephants and high-wire acts. Among the attractions arriving in town were two albino African-American men called George and Willie Muse, famous across the United States as Eko and Iko, the sheepheaded cannibals from Ecuador. But the Muse brothers weren’t from Ecuador: on that day, as their train pulled up, George and Willie were coming home.

Ringling Brothers circus pitched its tents on Roanoke fairgrounds where, a year before, thousands had attended a Ku Klux Klan rally, its leaders declaring then that “their organisation was simply to keep the states under control of white native Protestants”. The 13th amendment to the US constitution abolished slavery in 1865, but in the 1920s the south was at the height of Jim Crow segregation laws. “There was scarcely a white man in the south who did not honestly regard emancipation as a crime and its practical nullification as a duty,” wrote African American sociologist WEB Du Bois.

That duty was fulfilled thanks to a racist criminal justice system (Roanoke’s chief prosecutor at the time, for instance, was founder of the city’s KKK chapter) and to a sharecropping system called Reconstruction that kept black tenant farmers, many former slaves, in debt and beholden to their landlords. As a result, supposedly liberated African Americans were poor, in effect disenfranchised, often uneducated, and much more likely than white people to be in jail. The result was slavery by another name.

Eko and Iko were, writes Roanoke-based journalist Beth Macy in her new book about the brothers’ extraordinary lives, perfect freakshow acts to captivate white punters jaded by the usual fare of bearded ladies, tattooed men, giants and dwarves. Circusgoers were used to seeing black men posing as wild men in cages, where they would pretend to subsist on raw meat and bit the heads off chickens and snakes. Eko and Iko offered something different, if no less racist. “They were unique,” writes Macy. “They were good musicians. And they dressed in finery with red sashes and tuxedos – the outfit topped off by that explosive, anachronistic hair. They were far more interesting than they were grotesque.”

The brothers billed as Eko and Iko, sheepheaded cannibals from Ecuador. Photograph: PR

The Muse brothers had been encouraged to grow their hair into vast dreadlocks that they would tuck into enormous caps and then release before gawping punters. Dreadlocks, still less the sprawling golden dreads of the Muse brothers, were in those days an unusual sight, at least in the US, and white people would tug at them to see if they were real. Circusgoers would pay the equivalent of $30 in today’s money to be photographed with Eko and Iko.

But throughout their circus careers, George and Willie were often billed as things they were not. They were not only cannibals from Ecuador, but Monkey Men and Ministers from Dahomey. At one point newspapers gleefully reported the nonsense that John Ringling had found the two brothers floating off the coast of Madagascar. Their act was even given a racist, pseudo-scientific spin when they were presented as Darwin’s missing link between humans and apes.

In reality, George and Willie were two men from Virginia who, even as small children, had toiled from dawn to dusk in tobacco fields near their home in Truevine, Franklin County, walking rows of plants looking for bugs and squashing them between their fingers. Until, that is, the day in 1899 when George, six, and Willie, nine, were spotted by a “freak hunter” called James Herman “Candy” Shelton who, in the new film adaptation of Macy’s book, is likely to be played by Leonardo DiCaprio.

Shelton was looking for sideshow attractions as lucrative as the conjoined twins from Thailand who became the act Chang and Eng, or the dwarf brothers from Ohio, whom circus showman PT Barnum called the Wild Men of Borneo.

When Shelton came across the Muse brothers, he realised he had struck gold. Albinism is a congenital disorder more common among people of African descent than white Europeans – one in 10,000 of the former is born albino, compared with one in 36,000 of the latter. The most common mutation disables enzymes used in the making of skin pigment and hair colour. In the Muse brothers’ not-unusual case, the mutation also made them incredibly sensitive to light and very nearly blind.

The story told in Truevine is that he offered them candy as they worked in the fields and then kidnapped them. For years after their abduction, Shelton acted as the brothers’ manager as they toured the US in a series of circuses, using the money they earned to pay for their board, lodging and clothes, but never letting them have their wages. They were not seen again by their parents, Harriett and Cabell Muse, until autumn 1927.

With their parents, 1927. Photograph: PR

The brothers’ albinism helped the Muses to become not just circus attractions but also unwitting case studies for the US eugenics movement. In 1939, George and Willie’s photograph appeared in a textbook called You and Heredity, the picture supplied by the Ringlings’ publicity people. The author, Amram Scheinfeld, wrote: “They have white skins, pale blue eyes and flaxen hair (the odd effect produced by combing out the woolly strands and letting them grow for exhibition purposes). They also have nystagmus (oscillating eyeballs, characteristic of many albinos).” The purpose of publishing the picture in the book became plain when Scheinfeld wrote: “By sterilisation and birth control we might reduce the proportion of the ‘unfit’, and by stimulating births in other quarters we might increase somewhat the proportion of the ‘fit’.”

In the 1920s, George and Willie’s home state of Virginia was at the forefront of American eugenics. It introduced a programme that between 1924 and 1979 forcibly sterilised 8,000 people on the grounds of mental illness, physical deformity or even homelessness in the name of protecting the “purity of the American race”. That programme, Macy argues, provided inspiration for the Nazi sterilisation experiment in Hitler’s Germany.

When the circus came to Roanoke in October 1927, the brothers were being billed as something even stranger than Ecuadorian savages. “Are they ambassadors from Mars?” asked the poster of the brothers hanging outside the sideshow. According to the story, Eko and Iko had been spotted in 1923 climbing from a hole near the wreckage of their spaceship in the Mojave desert. The idea that these supposed Martians would be playing popular tunes in a tent in Virginia didn’t make a lick of sense, but that didn’t deter the crowds.

At Roanoke fairgrounds on that autumn day, George on mandolin and Willie on guitar were playing It’s a Long Way to Tipperary when one of the brothers noted something unusual – a black woman had managed to elbow her way to the front of the mostly white crowd. “There’s our dear old mother,” said George. “Look, Willie, she is not dead.” They laid down their instruments and rushed to hug the woman they had not seen for at least 13 years.

At the time, Harriett Muse was working as a maid and laundress in Roanoke and, though illiterate, had found out her sons were coming to town. George and Willie had been told that their mother was dead by Candy Shelton in order that they give up any dreams of going home.

While the legend around Truevine was that the boys had been kidnapped in 1899, Macy found accounts that Harriett had contracted with a carnival operator called Stokes for her sons to travel with them. Only later, according to those reports, had they been kidnapped by Candy Shelton. But certainly since 1914, when her sons had gone missing from the Great American Shows carnival, Harriett had had no news of her sons’ whereabouts.

A poster billing them as Martians. Photograph: PR

Were they kidnapped as little boys or, at least initially, contracted by their mother to a circus? Which story does Macy, who has been investigating the Muse brothers’ lives for the past quarter of a century, believe? She says she is unsure, adding: “For me, the point is, even if Harriett did permit her boys to join the circus, who am I or who is anybody to judge?”

“This was the racist world of To Kill a Mockingbird,” she adds. A time when, as one African-American interviewee told Macy, black children on their way to their segregated Roanoke school would pass a house owned by a white woman who had trained her parrots to squawk the N-word. Perhaps helping her sons to get away to the circus, thereby escaping this racist world and its dearth of opportunities for African Americans, was the best Harriett could do.

Whatever the truth of how George and Willie became Eko and Iko, certainly the brothers had been trafficked for at least 13 years when they were reunited with their mother. And on that autumn day, Harriett wanted payback. She was, clearly, an extraordinary woman: three days after she faced down the circus proprietors and city cops in that sideshow tent and reclaimed her sons, she started legal proceedings against the Ringling Brothers and Shelton. The brothers had been, her lawyer argued, held against their will, and turned into slaves. In a settlement, the circus agreed to pay back wages and, later, the kidnapper-turned-manager Shelton was dispatched to sweeten the deal: if the brothers returned to the circus, not only would a portion of their salary be paid to their parents, but their other brother Tom would be hired to work as a roustabout.

By winter 1928, the brothers had left home again and were touring once more with Ringlings. That year they appeared at Madison Square Garden and, according to the book’s dust jacket, then also “performed for royalty at Buckingham Palace”. When I ask Macy about this, though, she says she is not sure if they did – even though the brothers maintained in later life they had appeared before the king, the Palace has no records of such a performance.

In any case, what was more striking about Eko and Iko’s trip to London was that they were a flop. “The London public had no taste for that sort of thing,” wrote Cyril Mills, son of Bertram Mills at whose Circus Funfair at Olympia, they performed. Why? If the UK was, and is, scarcely any less racist than the US, Macy suggests, it had more advanced attitudes towards disability in the 1920s because so many of its veterans after the first world war were disabled.

Mills wrote: “We did not want objects of pity of any kind. In my opinion, Eko and Iko were severely handicapped mentally.” This assumption unfairly dogged George and Willie throughout their lives, but Macy denies that there is any evidence for it: “Uneducated, yes. Socially uncomfortable around white authority figures, yes.” But mentally handicapped? Not at all.

Back in the US, the Eko and Iko act proved lucrative for years, keeping them in work until the late 50s. Their father, depicted throughout Truevine as a dangerous spendthrift and wastrel, was murdered by a husband who found him in bed with his wife. Meanwhile, Harriett repeatedly used the law to ensure that her sons got paid, that the circuses they worked for informed her of their whereabouts, and that some of their earnings came to her. She used the money she saved that way to buy land in Franklin County, where she hoped she would see her boys later live. That was not to be: she died aged 68 in 1942. But the nest egg saved from her sons’ wages went towards buying a house in Roanoke where George and Willie lived in retirement, cared for by other women in their family.

A portrait of Willie a few years before his death in 2001 at the age of 108. Photograph: Josh Meltzer/PR

In becoming African American homeowners in 1961, the Muse brothers were unusual - the 1960 US census revealed only 38.1% of black households were homeowning, compared with 63.35% among whites. George died in 1972, but Willie lived on until 2001, when he died aged 108. In his last years, Macy relates, Willie would straighten the picture of his mother in a silver frame near the foot of his bed, and recall with with pride how she had stood up to the cops and circus bigwigs when she came to reclaim her sons in 1927. Willie managed to outlive everybody who had exploited him, including the only person he ever hated – Shelton. “Scum of the earth,” he would say of Shelton, or if he was feeling especially feisty: “Cocksucker.”

Surely, though, the world in which George and Willie were kidnapped and enslaved as circus freaks is over? So, why is the Muse brothers’ story worth telling in 2017? “We’ve erased so much of our history,” replies Macy. “Thinking about untold stories like these may help us understand the tension in this country.” She was writing the book at a time when 32 American states enforced new voter identification requirements that, she argues, disproportionately disenfranchise poor and minority voters. It was almost as if, she tells me, Americans wanted to make their country as segregated as it was in the Jim Crow south. She had long known that she had a good story to tell, but only in writing it did she realise how pertinent it was.

“I still think the country doesn’t want to talk about the early years of the last century, and what segregation meant, even though without understanding our history we are doomed to repeat it,” says Macy. “A lot of people I interviewed lived through the horrors of segregation. Almost to a person they told me that younger people don’t want to talk about it.” More than half of white Americans, she says, think the US spends too much time talking about race, while just 18% of black Americans do.

She believes many of those who voted for Donald Trump are like that – people who don’t want to have that hard conversation about America’s racist past and how it led to its racist present. On the day I interview Macy, the president signed his latest executive order blocking citizens of six predominantly Muslim countries from entering the US. “I’m scared that he’s creating an America like the one I write about,” says Macy. “He’s fanning the flames of American racism, attacking refugees and immigrants, splitting up families. He gets support for those policies from white people who often don’t know black people and whose worlds have become very small.”

Macy is now writing another book provisionally entitled Dopesick and dealing with the kind of people to whom Trump’s promises to make America great again and restore manufacturing jobs have proved seductive. “It’s a book about the heroin and opioid epidemic and something I have been reporting on since 2012. It’s a huge epidemic that is getting worse, and my book centres on communities of workers who’ve been sidelined by globalisation – the kind of people who turned the map of America red for Trump in the election.”Truevine was published in the US in October, just before Trump was elected president. Perhaps it would have been better for the story to have been written by an African American, since her book could be taken (albeit unfairly) as whitesplaining American racism, but that was not to be. Macy is pleased that her book is helping give a remedial education in American history to Americans, among them, she tells me, kids at a juvenile detention centre in Roanoke.

How has the book been received? “Some people have suggested I’m too hard on white people.” Are you? “I’m writing about a time of lynchings and racist parrots, so no, I don’t think so.” More importantly, what do black people make of it? In Macy’s acknowledgments, she quotes one African American describing her as “just another white person stirring up shit”. To be fair, that person was Nancy Saunders, the Muse brothers’ great-niece and one of their caregivers in their declining years, and let’s hope she wasn’t entirely serious. “I guess she’s right, I am a white person stirring up shit, but that’s OK.”

Truevine: Two Brothers, a Kidnapping and a Mother’s Quest: A True Story of the American South is published by Macmillan, price £18.99. To order a copy for £16.14, go to bookshop.theguardian.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min p&p of £1.99.