Muhammad Ali, the most famous Kentuckian, gets the Ken Burns treatment

Just as it has to be daunting for a contemporary author to choose to write about Abraham Lincoln, so must it be for documentary filmmakers to select Muhammad Ali as a subject.

When it comes to the two most famous Kentucky natives, is there anything left to say?

In the case of Ali — who died in 2016 at age 74 — you will soon find out.

This weekend, the famed documentary filmmaker Ken Burns, his daughter Sarah Burns and her husband, David McMahon, will unveil the four-part “Muhammad Ali.”

Six years in the making, the film starts Sunday and will run each night through Sept. 22 from 8 p.m. to 10 p.m. on PBS television affiliates, including KET. The documentary attempts to provide an overall context to the very large life lived by Ali, the Louisville-born boxing champion and a cultural lightning rod of the turbulent 1960s.

“We were, obviously, aware that there was lots of other stuff about Ali — and lots of really great stuff about Ali,” Sarah Burns said Monday in a phone interview. “But I also think we felt like there wasn’t something that really tied together all of these different pieces of Ali’s life as a way to understand him and his world and his context in a more comprehensive way.”

The Ali project was directed by Ken Burns and written and co-directed by Sarah Burns and McMahon.

By project’s end, McMahon says he came to believe that Ali’s life — including his conversion to Islam and alignment with Elijah Muhammad’s Black separatist Nation of Islam movement — is best understood through the prism of a man on a lifelong spiritual journey.

“As a teenager growing up in a (racially) segregated neighborhood in Louisville, his father is a frustrated (house) painter who isn’t getting the same opportunities as white painters,” McMahon says. “(Ali) is sort of aware of Emmett Till (a Black 14-year-old brutally murdered in Mississippi by two white men in 1955). So I think when he discovers the Nation of Islam, it helps him make sense of the world he inhabits.”

Ali’s quest for spiritual understanding continued throughout his life, McMahon says, and was on display when he followed W. Deen Mohammed, Elijah’s son, into a more mainstream practice of Islam.

“Toward the end of his life, (Ali) seems to be thinking about his faith all the time,” McMahon says. “When he is taking measure of his life, he is very thoughtful about what things he got wrong — how he treated the women in his life. How he treated (boxing) opponents like Joe Frazier. How he left it with Malcolm X (the two were friends, but had a falling out) when he was assassinated. And it was all toward considering the meaning of his life through the lens of his faith.”

One of the pleasures of the documentary is that it veers off to provide compelling portraits of Ali’s main boxing rivals — Sonny Liston, George Foreman, Larry Holmes and Frazier.

“We wanted to do a study of who (Ali’s) opponents were and render them in three dimension,” McMahon says.

Along with his conversion to Islam, the action that put Ali at the center of 1960s U.S. social turmoil was his decision, on April 28, 1967, to refuse induction into the United States Army during the Vietnam War.

Claiming conscientious objector status based upon his Islamic faith, Ali stood on his convictions at great personal cost. He was convicted of draft evasion, sentenced to five years in prison, fined $10,000 and banned from boxing.

“There was just so much at stake,” says McMahon. “When he fights Cleveland Williams shortly before he is exiled from the sport, you can see in the (documentary), he is so dominant. He is at the height of his athletic powers. It’s clear what he is giving up when he says ‘I am going to resist the draft.’”

It was three years before the U.S. Supreme Court overturned Ali’s conviction on a technicality and he got the chance to return to boxing.

“Clearly, he is not the same fighter,” Sarah Burns said of the post-exile Ali. “He’s a little slower, his legs don’t have quite the same speed. What it means is he has to find different ways to win. That’s both amazing because he does it, manages to win these big, dramatic fights.

“But on the flip side of that, it also means he is taking a lot more (physical) punishment. In the early part of his career, he barely got hit hard. He was not taking much punishment. After the exile, he is. And we saw the impact of that, later in his life (when Ali suffered from Parkinson’s Disease).”

While editing on “Muhammad Ali” was being done largely via Zoom during the coronavirus pandemic, the United States was enduring another reckoning around the issue of race. It followed the deaths of Black citizens such as George Floyd in Minneapolis and Breonna Taylor in Louisville as a result of interactions with police that went very wrong.

“I am sure Ali would be thinking about (racial issues in the U.S.) and be engaged with it if he were here today. I think he would have something to say,” Sarah Burns said. “(The recent social-justice advocacy) made us feel like it has never been more important to hear from Ali than it is right now.”

‘Muhammad Ali’

What: Ken Burns-directed four-part documentary about boxing champion from Louisville

When: Sunday through Sept. 22

TV: KET (8-10 p.m. each night)