Viola Davis to play Harriet Tubman for HBO

US actress Viola Davis is well known for award-winning roles in "Doubt" and "The Help."

Viola Davis has been tapped to play HBO's Harriet Tubman, the activist who helped create the Underground Railroad that allowed hundreds of slaves to escape to freedom.

Davis is developing the telepic with Amblin TV and writer Kirk Ellis, who helped write the HBO "John Adams" miniseries, and "Entourage" executive producer Doug Ellin, Variety reports.

The movie is based on Kate Clifford Larson's book "Bound for the Promised Land: Harriet Tubman: Portrait of an American Hero."

The movie is in an early development stage and could begin filming during Davis's hiatus next year from her ABC drama "How to Get Away with Murder."