'Maybe, he wasn't the problem. Maybe, I was': How Muhammad Ali stayed true to himself on his path to becoming an icon

Muhammad Ali scoops up his baby daughter Maryum and explains a concept that she couldn't possibly understand at such a tender young age: "Your daddy is fighting for you," he is reported as saying in 1968. "Someday, you're going to be able to walk with your head high and not beg for a job. And you don't even know it."

Between 1960 and 1981, Ali fought 61 professional heavyweight bouts in a glittering career that made him a global icon, but arguably his biggest fights were outside of the ring. His remarkable life story is once again in the spotlight, the subject of "Muhammad Ali" -- an expansive, four-part, eight-hour documentary by the renowned filmmaker Ken Burns, airing on PBS.

"He intersects with all of the things that not only were the most important issues of that day," Burns told CNN Sport, "He's so much bigger than boxing. Sports and the role of sports and society, Black athletes and race and religion and faith and politics and war. There isn't a button that he doesn't push, either deliberately or accidentally -- and he's so amazing."