Joe Frazier

Ali at the center of any talk of activism by black athletes

Muhammad Ali knew he didn't have much time left. His career was at stake — but more importantly, so was his freedom — as he awaited the day he would formally refuse to be inducted in the armed forces of the United States.

So he embarked on a grand tour to make some money before his fighting days came to an end.

The heavyweight champion fought in a soccer stadium in England, and at an ice rink in Germany. He defended his title twice in the sparkling new Astrodome in Houston, part of a flurry of seven bouts in less than a year.

Revered by many at his death, Ali was equally reviled at that time. Like many black athletes who stand — or take a knee — to speak out for...