When four young girls dressed in their Sunday best walked on screen ten minutes into Selma, I knew what was coming next, which didn’t make what then happened any less shocking. When the bomb went off, I leapt in my seat.

Addie Mae Collins, Denise McNair, Carole Robertson and Cynthia Wesley were murdered on September 15 1963, when a bomb planted by members of the Ku Klux Klan exploded beneath the steps of the 16th Street Baptist Church in Birmingham, Alabama. 16th Street was an African-American church used as a meeting place by Civil Rights organisers during their long campaign for voter registration and desegregation in the American south. The girls were there for Sunday school. The church clock stopped at 10.22am.

‘Death comes to the innocent and it comes to the guilty,’ Martin Luther King told mourners during his public eulogy for the murdered girls. ‘Death is the irreducible common denominator of all men.’ Death is something Selma takes seriously. The film never for a moment loses sight of the fact that people – black and white, but mainly black – died for the cause of Civil Rights. There is violence in this film, and it is horrific, and individuated, which sets Selma apart from all manner of Hollywood blockbusters in which death becomes a numbing spectacle. The assassination of Martin Luther King looms over the film – beyond its timeframe, but known to us all.

How to approach a figure with the reputation of a secular saint? One achievement of Selma – and it is a film of many achievements – is to reanimate King as a living, breathing man; a man of politics, strategy, and absolute, underlying resolve. Selma gives back to the Civil Rights movement its urgent and motivating anger, when too often the movement has been misrepresented as a cause of infinitely patient, infinitely forbearing martyrs. Time was not on the activists’ side. ‘For years now I have heard the word, “Wait!”,’ wrote King in 1963, while he was imprisoned in Birmingham jail. ‘It rings in the ear of every Negro with piercing familiarity. This “Wait” has almost always meant “Never”.’

Selma makes this political tension the film’s central dramatic tension; between those who say, “Wait” – particularly the kind of white moderate who, in King’s words, ‘paternalistically believes he can set the timetable for another man’s freedom’ – and those who cannot wait, because they might die waiting. Mostly, this tension plays out in meetings at the Oval Office between King (David Oyelowo) and President Lyndon B. Johnson (Tom Wilkinson). Selma’s portrayal of Johnson as someone genuinely committed to the passage of the Voting Rights Act, but nevertheless prepared to schedule it somewhere behind his own legislative priorities, has brought the film a bucketload of trouble in the United States. Supporters and former employees of the now-deceased President have condemned Selma’s inaccuracies of detail, while ignoring both the film’s larger truths, and the fact that Johnson did want to wait on the Voting Rights Act, which was eventually passed in 1965.

Johnson is not the film’s white saviour – but then, King is not presented as a saviour, either. Selma emphasises the tactical disagreements between King’s Southern Christian Leadership Conference (SCLC) and young members of the Student Nonviolent Coordinating Committee (SNCC), who had spent years organising in Alabama before King’s older, more powerful organisation came to town. There is also a tense meeting – which really took place – between King’s wife, Coretta Scott King (Carmen Ejogo) and Malcolm X (Nigel Thatch). The scene suggests, intriguingly, that Malcolm X was willing to be demonised for the sake of furthering the Civil Rights movement as a whole: he would play the white folk’s devil, and King the better angel of their consciences. A few weeks after this meeting, Malcolm X too would be murdered.

The complicated history of the Civil Rights movement will be less well-known to Australian viewers than to American ones, but Selma manages a difficult synthesis between dramatic elegance and historical knottiness. Through it all threads the story of three protest marches from Selma to Montgomery in 1965 – one bloody, one aborted, and one triumphant. It is in triumph that the film loses momentum; though Selma does so well, for the most part, at avoiding obvious peaks, the final twenty minutes are filled with speechifying, first by Johnson and then King.

David Oyelowo’s absence from the Oscar nominations list is mystifying and embarrassing. His portrayal of Martin Luther King is dynamic but also nuanced – it’s a less self-consciously mannered performance that Benedict Cumberbatch’s in The Imitation Game, and a far less self-congratulatory one than Michael Keaton’s in Birdman. Carmen Ejogo, too, should have been nominated as supporting actress: she plays Coretta Scott King as a woman with courage equal to her husband’s, but hemmed in by the pressure of her domestic responsibilities.

Filmmaker Ava DuVernay is that still-rare person in mainstream cinema: an African-American female director. She has not been nominated for an Oscar – in the history of the Oscars, only four female directors have been nominated for Best Director, and none of them have been black. Significant black female directors like Julie Dash (Daughters of the Dust) and Cheryl Dunye (The Watermelon Woman) remain little-known outside the world of cinephiles. The struggle for racial equality depicted in Selma is not only a historical lesson – it is an ongoing reality.