Dolores

"All that a person has is his or her story... and when you take away their story, you take away their power."

So says Dolores Huerta in this timely documentary from Peter Bratt, and although she's not speaking about herself, she would know it better than most. In 1962 she co-founded America's first farm workers' union, though it was her colleague Cesar Chavez whose name became associated with it. Outside the movement she was best known for what newspapers presented as a scandalous personal life, with three husbands and 11 children and a refusal to comport herself in the way a woman was expected to. Inside it she was respected as a highly efficient organiser with a vision and a strength of will that few could equal.

It was a vision she wasn't shy about explicating. She believed that the alternative to capitalism was revolutionary socialism. It appalled her that the people on whom America most depended - those whose hard work ensured that everyone else could eat - were paid its lowest wages. Determined to bring about change, she launched a series of strikes, but what she hadn't foreseen was the ferocity of the response, nor the level of cooperation between business leaders and the state in attempting to preserve the status quo.

Bratt's documentary may seem fairly formulaic with its linear narrative and mixture of talking heads with archive footage, but it is significant both in raising the profile of a woman too long overlooked and - crucially - in giving her back control over her own story. An octogenarian now, she makes only brief comment, but her presence is felt throughout. As the story goes on, Brett illustrates the impact she had on American life first by showing us the figures who sought to oppose her - such as Ronald Reagan - and then by introducing those she influenced. In one of the clips that may be better known to today's audience, a bashful Brack Obama apologises to her for stealing her slogan, Sí se puede - yes we can.

Though many viewers will approach this as the story of a hero, Bratt takes care to show us Dolores' human side: the conflict she felt between her duties to her family and to her people, the weight of ongoing responsibility that she recognised each time she was offered a new leadership role. He gives the impression of a woman who did what she did not so much because she wanted to as because she could and somebody had to. But we also see her unwillingness to compromise her authenticity in order to win societal approval, and it is her resistance on this point that made her iconic as a role model for women - especially brown-skinned women who had even fewer opportunities than their white counterparts.

Racism is a constant presence in the story. Latino and Hispanic workers looked to African Americans for examples of how to throw off oppression, but America's white population seemed even less prepared to countenance their rejection of accepted social roles. Indeed, this struggle has been poorly documented to date, which is another reason why this film matters. It makes its own contribution to the justice that Dolores sought, and it fills in a gap in American history.