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 political or social change, he paid a price for his actions.
But he never wavered, despite nearly going bankrupt and drawing the wrath of a good portion of a country that viewed him merely as a draft dodger.
He had announced after beating Sonny Liston to win the heavyweight title in 1964 that he converted to Islam and was a follower of the Nation of Islam.
"He believed 1 million percent," said Gene Kilroy, Ali's longtime business manager. "He never wavered because he believed Allah was on his side. People didn't believe him, but he believed."
Kareem Abdul-Jabbar said it was important for black athletes to stand with Ali, to show he had support within his community.
"That was important because America didn't think black Americans had any voice whatsoever," the basketball legend said. "We had no political muscle. No legal means to help the brother. But we let him know that we were behind him and eventually he won his case."
But Ali lost the heavyweight title and three years of what would have been the prime of his career during his forced exile from the ring.
The 70-year-old Abdul-Jabbar, who has had conversations with Colin Kaepernick , said the former NFL quarterback who sparked league protests by kneeling during the national anthem before games, is paying a similar price.
Ali "sacrificed a lot to take that position," said Abdul-Jabbar, author of "Becoming Kareem: Growing Up On and Off the Court." ''That was a great sacrifice on his part. That was the height of his career in his mid-20s, the heavyweight champion of the world.
"The same thing happened to Colin. Anybody that knows anything about football will tell you that he is a talented athlete and should be on somebody's team."
Black athletes have a storied history of being sidelined for speaking out , dating as far back to Jack Johnson in the early 1900s.
"It's a testament to their commitment, their courage, their intellect, their understanding of the issues, and their potential role in rectifying some of these challenges that you have people like them in those positions who are willing to pay that price," said Harry Edwards, longtime civil rights activist and a sociology professor emeritus at University of California, Berkeley.
None stand taller than Ali.
Ali's final fight in the ring before taking on the government was at Madison Square Garden, where he punished Zora Folley before stopping him in the seventh round to remain unbeaten.
"What's my name?" he kept asking Folley, who had refused to call him by his adopted Muslim name.
Folley wasn't alone. No one knew what to call this heavyweight champion, or for that matter knew what to think about him.
The Associated Press used his birth name, Cassius Clay, in the story that fateful day in April 1967 in Houston. But as he stood with 11 other inductees, the U.S. government called upon Muhammad Ali not once but three times to take a step forward for induction in the U.S. Army.
He didn't take the step. His religion, Ali said, did not allow him to kill in Vietnam in the name of others.
"I am going to die a Muslim," he said the day before. "They don't think I'm serious. I will show them I am."
The decision never cost Ali a day in prison, even though he would be sentenced to serve five years for draft evasion. The U.S. Supreme Court later overturned his case on a technicality.
He didn't set out to be a game changer. Ali wanted little more than to be the heavyweight champion, and to be free to practice his religion.
"I don't have to be what you want me to be," Ali said. "I can be what I want."
But with the war raging, the Army needed recruits — and lots of them. Ali had been disqualified for service after failing an intelligence test, but the standards had been changed by the time the government came around to having him take it again — and this time he passed.
Ali was not going to go, something cheered by a small group of protesters in Houston but widely criticized by much of mainstream America.
"'Take my tail and put it in jail,' he would say," Kilroy recalled. "We would discuss the Vietnam War and how the rich people in Vietnam went to Paris to live and our guys went over there and got killed. It wasn't fair and Ali knew that."
He spent his time in exile traveling to visit sick kids in hospitals and speak at college campuses. Kilroy was often at his side as Ali tried to make a few bucks with a sometimes confusing message that included his view at the time that the races should be separated.
"I know blacks and whites cannot get along," he told The Boston Globe. "This is nature. It just gets worse every day."
He would later be revered for taking a principled stand. Indeed, Ali would have gone to prison for his beliefs, though during much of the three years in exile he seemed just as concerned with making a living as he did with changing society.
Still, he managed to put words together that that perfectly expressed the views of many blacks, who made up a disproportionate percentage of draftees during the war. They came from the teachings of the Black Muslims, but somehow coming from Ali they seemed less threatening to the nation.
"Why should they ask me, another so-called Negro, to put on a uniform and travel 10,000 miles from home and drop bombs and bullets on brown people in Vietnam while so-called Negro people in Louisville are treated like dogs and denied human rights?" he said.
Ali would eventually fight again — and do so magnificently at times. He stopped George Foreman in Zaire, nearly fought to the death with Joe Frazier in Manilla.
But he would never get his three years of exile back, and the many punches he took in his return ended up taking a big toll.
He never stopped advocating for his religion up until the time he died at the age of 74, his voice long since muted by the effects of Parkinson's.
"He never had one regret," Kilroy said. "He was convinced that there was a power above us that takes care of everything. And for Muhammad that was good enough."
AP National Writer Errin Haines Whack and AP Sports Writer Kyle Hightower contributed to this report
EDITOR'S NOTE: African-American athletes have used their sports platforms for more than 100 years to impact social and political change. As part of AP's coverage plans for Black History Month, we will take a multiplatform look at how many have and continue to engage in activism, from Jack Johnson, to Muhammad Ali to Colin Kaepernick. https://apnews.com/tag/GameChangers