Writers, scholars, fighters and Muhammad Ali’s family weigh in on the legendary boxer’s life and career in an exclusive preview of Ken Burns’ upcoming film “Muhammad Ali,” premiering on Sept. 19 on PBS.

“There are many, many films about Muhammad Ali,” Burns says in the preview. “We think we tell a story in a kind of complete way.”

The four-part documentary, which includes interviews never-before-seen footage, tackles all aspects of Ali’s life. According to the late boxer’s daughter Rasheda Ali, “This film, it’s the whole picture. It’s the good, the bad, the inspiring … it’s everything.”

In development for six years, the documentary dives into the most dramatic moments of Ali’s career, including his fights against Joe Frazier and George Foreman, as well as his principled resistance to the Vietnam War and commitment to his Muslim faith. Burns co-directed and served as executive producer on the project, with Sarah Burns and David McMahon co-writing, directing and producing.

Leading up to the film’s premiere, Burns will join PBS and The Undefeated for “Conversations on Muhammad Ali,” which will preview clips of the documentary and feature sports and entertainment figures, scholars and writers.

“Muhammad Ali was the very best at what he did,” Ken Burns said of the project. “He was arguably America’s greatest athlete, and his unflinching insistence that he be unabashedly himself at all times made him a beacon for generations of people around the world seeking to express their own humanity.”

Describing the film in the preview, Burns adds: “Maybe you’ll come for the boxing, maybe you’ll come for the religion, maybe you’ll come for the politics or the conflict, but I think you’ll leave with an elevated sense of an amazing American.”