Why a new film about Harriet Tubman focuses on freedom

The Underground Railroad's most famous conductor, Harriet Tubman, is featured in a new film -- the first to share her story on the big screen. Director Kasi Lemmons and actress Cynthia Erivo, who stars as the title character in "Harriet," sit down with Amna Nawaz to discuss balancing biography and action, how they researched the project, the criticism they've received and the film's "female gaze."