Los Angles (COT): Jessica Chastain is in negotiations to play the real-life artist who became Native American leader Sitting Bull’s personal assistant. If she signs on for the role, The Martian star will portray Caroline Weldon, a 19th-century Brooklyn artist and activist who moved to the Standing Rock Reservation in what is now South Dakota to help Sioux chief Sitting Bull fight to keep his tribe’s land. Weldon was dubbed Sitting Bull’s white squaw as she fought for the rights of the Sioux, while living among them. Woman Walks Ahead will be directed by Nanny MCPhee’s Susanna White from a screenplay written by Peaky Blinders creator Steven Knight, according to The Hollywood Reporter. Chastain would play Caroline Weldon, a 19th-century Brooklyn artist and activist who moved to the Standing Rock Reservation in Dakota Territory to help Sioux chieftain Sitting Bull fight to keep the land for his people.

She would write letters to the federal government on behalf of Sitting Bull and eventually lived on the land with her teenage son for several years, even though she was vilified by the press, which called her “Sitting Bull’s white squaw.” Ed Zwick, Marshall Herskovitz, Rick Solomon and Erika Olde will produce the film. IM Global is selling the film, and will introduce it to buyers at EFM in Berlin. CAA is packaging and representing domestic rights. Black Bicycle Entertainment is financing the project.

The move brings back to the life the project that has been around for at least a decade and at one point had Tom Vaughan (Starter for 10) attached to direct.

Chastain was most recently seen in The Martian and Crimson Peak. Her upcoming films include The Zookeeper’s Wife and The Huntsman Winter’s War. She’s also attached to Miss Sloane and The Death and Life of John F. Donovan. She’s repped by CAA, Mosaic and Hansen, Jacobson.