In my lifetime, the horrors of slavery have rarely been acknowledged. While every child knows of the evil and atrocities the Nazi’s are responsible for, the brutality and abuse of slavery is a history that has only recently re-emerged.

Even when it did, between 12 Years a Slave and Django Unchained, some condemned its angry sentiments, as if there was a sin committed by even bringing up the topic. Ava DuVernay’s 13th, on the other hand, is not one single story or a fictional endeavour. 13th explains the consequence of slavery and the relationship it has with the grotesque treatment of African-Americans today.

Beginning with the 13th amendment, there is a focus on the caveat that, though “involuntary servitude” won’t exist, there is an exception to the rule: “Except as a punishment for crime whereof the party shall have been duly convicted”. Through interviews with a diverse range of academics and civil rights fighters, there is a history of slavery itself – and how ending this created chaos in the southern states. Entire economic systems suddenly disappeared overnight and people, who were considered property, were now roaming free. It is difficult to imagine the cultural shift that was forced onto people. Due to the southern states refusing to abide fully by the changes, black families migrated north to create communities in cities all across America (something that connects 13th to the magnificent OJ: Made in America). But the abuse still continued in a variety of forms: Jim Crow, segregation and, in the modern era, the justice system.

13th begins with the shocking statistic, read by Barack Obama, that although America has 5% of the population among its free nation, 25% of the world’s prisoners are within the United States of America. Over 2,000,000 people, locked behind bars with that ugly stain of criminality stuck against them for the rest of their lives. Crucially, it disproportionally affects men and women of colour. If you are white, there is a 1 in 17 chance that you’ll end up in prison. If you are black, it’s 1 in 3. That is a shocking, horrific statistic. But Ava DuVernay refuses to rely on these exclusively, filling in the gaps with the history in between. From the Civil War to Civil Rights. From Nixon to Reagan and to Bill Clinton. The refusal to tackle discrimination, that’s continued in different forms since slavery, has left generation upon generation robbed of a future.

Cotton-picking was an enormous part of the slave trade but prisoners now create clothes for JC Penney and Victoria’s Secret (something Netflix’s Orange is the New Black tackles). Companies, as they did hundreds of years ago, profit from placing people in prison and DuVernay’s detailed attack on A.L.E.C. is only scratching the surface in the corporate control of the USA today. The recent riots and ‘Black Lives Matter’ movement is not responding to a single event: it is following centuries of abuse that minorities have had to endure.

13th eventually connects to 2016. Since the Ferguson and the murder of Trayvon Martin, we have seen regular videos uploaded onto YouTube showing police officers shoot and murder black men. This has only happened because those standing by own video-taking smart phones. Remind yourself: this has been happening for hundreds of years. There is no ‘rise’ in police violence; there is a rise in videos revealing police violence. The rise in the right, fuelled by the racist rhetoric of Donald Trump, DuVernay expertly collages together in the final act of 13th. This is where her expert direction weaves the many strands together. 13th smoothly plays as an informative, revealing history documentary but the gut punch is at the end, when the truth is how we still live in such divided times.

The ugliness has bubbled to the top but, when you watch Boyz N the Hood (a re-release part of the BFI’s Black Star season), you realise that since 1991, nothing has changed – only more people are in prison. And the prison numbers are terrifying. This is must-see, vital viewing and 13th will end up on most end-of-year lists (at the top of many, no doubt) with its demand for change. 13th is a magnificent achievement and, alongside OJ: Made in America, it will reshape the conversation about (and fight against) racism and discrimination across the world.

This was part of the London Film Festival 2016 coverage for Culturefly