Oscar-nominated star Viola Davis is preparing to walk a mile in Harriet Tubman's shoes after being cast as the abolitionist hero in a forthcoming HBO movie.

Deadline reports that The How To Get Away With Murder actress will take on iconic role of the African-American activist in the yet untitled movie when it premieres later in 2015.

Born a slave, Tubman helped devise a network of secret routes, known as the Underground Railroad, which enabled hundreds of slaves to escape to freedom. She later served as a cook and a nurse and eventually a spy for the Union Army during the Civil War.

Davis is expected to co-executive produce the project along with her husband, Julius Tennon, Darryl Frank, Justin Falvey, Doug Ellin, Jim Lefkowitz and Cliff Dorfman. Famed screenwriter Kirk Ellis, who is the man behind acclaimed HBO miniseries John Adams, has been enlisted to write the script.

The film is based on the biography Bound For The Promised Land by historian Kate Clifford Larson.

Meanwhile, the 49-year-old star has been busy also developing a feature film based on the life of pioneering congresswoman Barbara Jordan.