When Jeanine Cummins logs in to our video call, I am surprised to see that the profile picture that pops up before her video loads is the Spanish-language cover of her book American Dirt. I had assumed, given the vitriol that novel attracted when it was published in 2020, that she would be trying to distance herself from it.

For the first year after its publication, that was the case, she tells me from a light-filled, bookshelf-lined room in her New York home. “My husband would ask me every week: ‘Knowing what you know now, would you still write it?’” she says, and the answer was consistently: “No, I would not.”

Eventually that answer shifted to maybe, and now, five years on, the 50-year-old author is firmly at yes. “I’m really glad I wrote that book,” she says. “I’m proud of it. But having to endure the experience of publication, it was brutal.”

American Dirt had been expected to be one of the buzziest books of 2020, having reportedly earned Cummins a seven-figure advance. Copies of the novel, about a mother and son fleeing a drug cartel in Mexico, arrived in bookshops emblazoned with a quote from the thriller writer Don Winslow, who called it “a Grapes of Wrath for our times”, and it was chosen as an Oprah’s book club pick.

“The kind of praise that it got was so over the top,” Cummins says now. She wasn’t used to the attention – her three previous books had not received anywhere near that level of hype – and she certainly wasn’t prepared for what came next: a string of bad reviews, one calling the book “trauma porn”. Whether Cummins had the right to tell the story of Mexican migrants, being neither Mexican nor a migrant herself, was called into question, and 141 writers signed a letter to Oprah Winfrey, asking her to remove it as a book club pick.

None of this was helped by the way Cummins’s publishers marketed the book, with barbed-wire centrepieces decorating a launch event, or the novel’s author’s note, which the writer now thinks opened the door to scrutiny.

In it, Cummins, whose grandmother was Puerto Rican, wrote that she “wished someone slightly browner than me” had written the novel, but added: “if you’re a person who has the capacity to be a bridge, why not be a bridge?” She also explained that her husband had been an undocumented immigrant in the US – but didn’t mention that he was white, and that his country of origin was Ireland.

“I was trying to justify my right to write that book and I didn’t need to justify it. It’s a novel. I’m allowed to write it.” She will continue to write characters who share different experiences from her, she says, and “would encourage every other writer out there to do the same”, as long as they do so with tremendous care.

It was her publisher who encouraged her to expand on the author’s note, which in the original manuscript was a one-line statistic about the number of migrants who had died in the US-Mexico borderlands. Before the book was sold, when she was taking meetings with the numerous editors who were interested in buying it, “every single one of them said: ‘Why did you write this book? Why?’” She felt she was being pushed to come up with a personal link to the story, when really she was thinking, given what was going on at the border: “Why isn’t everyone writing this book?”

Addressing “this enormous humanitarian stain on our national conscience” was the real reason she wrote American Dirt, Cummins says – and the reason she remains proud of it.

For her, it was “a very personal book”, because it was written just after her father died suddenly while out with friends. It was only later, after someone pointed it out to her, that she realised all the book’s major characters are grieving for their fathers. “So the notion that I was writing trauma porn or that I was unqualified to write about grief was really absurd,” she says.

Much was made at the time of the fact that she had referred to herself as white in a 2015 New York Times opinion piece about the murder of two of her cousins, the subject of her first book, the memoir A Rip in Heaven. “I have always been white. I will always be white,” she says now. “I have always been Latina. I will always be Latina. Those things are not mutually exclusive. I couldn’t believe that in 2020 I had to say Latino people come in different colours.”

The question of which ethnic group the author belongs to is one that has come up throughout her life, and is a major theme in her latest novel, Speak to Me of Home, in some ways a product of her post-American Dirt “soul-searching”. The intergenerational saga follows an Irish‑Puerto Rican family that closely reflects Cummins’s own – nobody can this time accuse her of writing outside of her own experience. “It’s unassailable in that particular way, which is a comfort,” Cummins says, though “that’s not why I wrote it”.

The character of Rafaela is partly based on Cummins’s grandmother, who was born into a well-to-do family in Puerto Rico, a “cherished and coddled oldest child” until her father “lost everything” when she was a teenager, and she was sent to the US naval base in Trinidad to work. There, she met Cummins’s grandfather, and the couple “ended up in St Louis with eight kids”.

At one point in the novel, Rafaela’s husband is asked by the manager of a “whites only” country club for proof that Rafaela is white. In the end, she is allowed to become a member, but must change in the staff locker room. “That’s a true story,” Cummins says – the same thing happened to her grandmother. Rafaela’s children being banned from speaking Spanish at home in order to fit in better at school is also taken from real life – Cummins herself was only allowed to speak English at home. And like Rafaela’s daughter Ruth, the writer felt like a fraud in all of the social groups at university, where everyone seemed to gravitate towards sororities or fraternities “where everyone looked exactly like them”.

Having grown up in Gaithersburg, Maryland, widely recognised as one of the most racially diverse US cities, Cummins was shocked by the way her fellow students at Towson University in Baltimore segregated themselves. “I’ll never forget being in the dining hall for the first time,” she says, where Black students were sitting in one room, white students in another. “And then there were a few tables in the corner for whoever was Asian or Latino, not Afro-Latino. And I was like, where do I sit?”

She and her boyfriend at the time, who was Black, tried to set up a club, “Target Unity”, with a view that it could be “a social outlet where people could mix and mingle with people who were not from their same racial, ethnic, or socioeconomic background.” They rented a room in the student union, but “no one came … no one wanted that”.

Cummins went on to work in publishing for a decade, so she was “acutely aware that publishing had a race problem”, but it “felt very weird” to be a focal point of that criticism – American Dirt sparked a wider global conversation about race and publishing, out of which the #DignidadLiteraria campaign for greater Latino representation in US publishing was launched.

Now her feelings about the book are bittersweet. Commercially, American Dirt was a huge success, something the author wasn’t able to feel excited about at first. She was “relieved” rather than happy every week it continued to be a No 1 bestseller. Though she doesn’t read media coverage or online reviews, occasionally her husband will send her a screenshot “if there’s something really lovely”. Yet so often these positive reviews “are defending my right to author the book”, she says, which she finds “really bothersome”. When reviewers say things like “it doesn’t matter that she’s not Latina”, they are still viewing her identity differently from the way she identifies herself: Irish and Puerto Rican; white and Latina.

“The book won,” she says. “It’s sold three and a half million copies and continues to sell.” But “in those moments, I realise I lost”.