Starring Cynthia Erivo. Rated PG

The story of Harriet Tubman is so inspiring, rich in historical importance, and crucial to battles still being fought for the American soul, you’d think her saga would be told more often.

Remarkably, the best-known version has been a 1978 TV miniseries, A Woman Called Moses, which starred Cicely Tyson, fresh from the widespread popularity of the Roots miniseries. (She also played Coretta Scott King in the same year.) This is odd, considering that Tubman personally rescued more than 70 slaves without losing any, while strengthening what became known as the Underground Railroad to Canada. She later became a Union spy during the Civil War (Drunk History did a good job with that), and an outspoken suffragist in the early 20th century, living to be 91.

This was despite seizures that resulted from a brain injury, at age 13, when an “owner” struck her with a heavy metal object. The movie Harriet understandably focuses on a fairly narrow band of action. Despite some controversy over having this American icon played by England’s Cynthia Erivo (so good in Bad Times at the El Royale), she’s mostly impressive as Tubman—at least once the former Minty Ross escapes Maryland and becomes the dagger-carrying renegade of legend.

The movie is less convincing about her private life, not least because this is more a matter of conjecture for director Kasi Lemmons, who cowrote the original script with Gregory Allen Howard (Ali, Remember the Titans). To put it bluntly, the material involving the future Harriet and her family is pretty boring compared with the derring-do to come. But the whole package is disappointingly conventional, with the usual drone shots, sweeping orchestral score—not a hint of Africa to be heard—and the stolid speech-making you expect from a routine biopic.

There’s barely a moment spared for the sense of displacement, let alone wonder, felt by a woman born in chains and suddenly exposed to luxurious food, clothes, and lodging, as well as the respect of a mixed society. Instead, you get painterly tableaux with “historical” figures standing stiffly in their costumes, intercut with far too many return trips to the exact same locations, and dreamy scenes depicting her seizures, which she attributed to a special relationship with God.

The movie hammers home parallels with Joan of Arc, but by reinforcing her mystical qualities, it undermines her stunning efficacy as a real person who simply, and fiercely, had the courage to act.