It’s hard not to notice that “12 Years a Slave,” arguably the greatest depiction of the American sin of slavey, comes courtesy of British filmmakers with roots all over the world. London-born director Steve McQueen’s family is from the Caribbean; the film’s star, Chiwetel Ejiofor, was born in London to Nigerian parents. Co-stars Lupita Nyong’o and Adepero Oduye hail from Africa.

“There is no part of the road that isn’t touched. We are all children of the diaspora,” said Oscar-nominated actress Alfre Woodard, who describes herself as a descendant of Southern sharecroppers and who plays Mistress Harriet Shaw in the film.

“12 Years a Slave,” which won the Audience Award at the recent Toronto International Film Festival (TIFF), is based on the 1853 autobiography by Solomon Northup.

Northup (Ejiofor) is a free man and violinist living a genteel life with his family in upstate New York in 1841 when he meets a pair of circus performers who hire him to play for their act. But they turn out to be con men who kidnap Northup and sell him into slavery. He’s shipped into the Deep South, where he endures a nightmare of brutality and inhumanity, mostly at the hands of a slave owner named Edwin Epps (Michael Fassbender). Northup is an educated, compassionate man forced to hide his intelligence and his compassion and use his wits to survive.

“I liked the idea of a free man who gets incarcerated. By doing that, the audience participates in the journey. I hooked up with John Ridley, who wrote the script. My wife had found this book and as soon as it was in my hands, I knew—it was a revelation with each turn of the page,” said McQueen in an interview at the TIFF. His past films include “Hunger” (2008) with his go-to actor Fassbender as IRA hunger striker Bobby Sands, and “Shame” (2011), in which Fassbender portrays a man with a sex addiction.

Shot in Louisiana, McQueen’s unflinching depiction of plantation life does for slavery what “Schindler’s List” did for the Holocaust. He says that American audiences just might be ready to take such a hard look into this history. “America has a Black president. There’s the unfortunate situation with Trayvon Martin, and it’s also the anniversary of the March on Washington. With that perfect storm, people are ready to receive and look and reflect on the past when maybe before they were not,” he said.

It is an understatement to say that McQueen asked a lot of his actors. “12 Years a Slave” is so gripping and disturbing that even though you want to look away, you can’t take your eyes off the screen. But the director was characteristically blunt when asked how he got his stellar ensemble to trust him. “That’s what actors do. That’s their job. You just do it,” he said. “Do the job, do a good job. End of story.”

Ejiofor, whose stirring performance as Northup earned him Oscar frontrunner status, said that he approached the job by reading Northup’s book. “It’s extraordinary; it’s a gift with such real insight. It should be in every school. I was primarily taken with that, to get underneath Solomon’s skin and find how he was able to survive something like this with his brain intact.”

Ejiofor said that just before shooting “12 Years a Slave,” he was in the Calabar region of southeast Nigeria making “Half a Yellow Sun,” which also played at TIFF. “Just before flying to New Orleans, I visited the slave museum, from where many slaves were taken and sent to New Orleans. So I took that same journey, and I was aware that this is a story about a diaspora as well as an individual,” he says. “Then I traveled to plantations to get a sense of the overall history and read different slave narratives, which was a compelling experience. And working with such an exceptional group of people makes the job so much easier.”

Woodard said that her character, a slave who “marries” her master and thus becomes a plantation mistress, “shows the complexity of slavery.”

“It was an economy for 300 years. She lived in a separate universe, right in the middle of everything,” Woodard said of the character.

One of the breakout performances in the film belongs to Lupita Nyong’o, who plays a young slave, Patsey, who is repeatedly raped by Epps, who then inflicts vicious beatings on her.

Nyong’o is a Kenyan actress and graduate of the Yale School of Drama, and McQueen cast her after seeing hundreds of auditions. Nyong’o said the actors bonded offscreen, which enabled them to trust each other.

“Michael and I made nice before we did our scenes, and I trusted him as a scene partner in order to be able to go there,” she said. “The first thing I did to prepare was visit the National Great Blacks in Wax Museum in Baltimore to get a 3-D experience. I read other slave narratives such as ‘Incidents in the Life of a Slave Girl.’ But mainly, it was how Solomon described Patsey as having ‘an air of loftiness.’ I understood she could be genial and pleasant and still want to die. That complexity is something, as an actor, you can only dream of.”

McQueen shrugs off accolades and talk of awards, saying he only wants Northup’s book to return to the bestseller list, where it was after Northup first wrote it. “I was surprised that no one knew this book. It’s a genius book,” McQueen said. “Scholars knew about it, but it’s not a classic like ‘The Diary of Anne Frank.’ I want to get this book into every school in America; that was always my aim.”