By Ben Dirs
BBC Sport in New York
Roy Jones turned professional after winning silver at the 1988 Olympics
"I say get an education. Become an electrician, a mechanic, a doctor, a lawyer - anything but a fighter."
So said Muhammad Ali when asked many years ago if he thought young African-Americans should consider following in his giant footsteps.
You might have expected Ali, who recognised more than most that his fellow black men and women were capable of great things, to add "President of the United States" to his list. But not even he could imagine anything as remarkable as a black man in the White House.
For many young black men in the 1960s and 70s, when Ali was 'The Greatest', becoming a champion in the ring was their sole ambition, largely because the deeply stratified nature of American society denied them any other.
Joe Frazier was the son of southern sharecroppers. The young Marvin Hagler's Newark tenement was razed during riots. Mike Tyson was a "wild kid running the streets" of Brownsville.
An electrician? You might as well have suggested to the teenage Tyson that he pursue a career as an astronaut.
And so, in the words of one American journalist, black fighters "owned" boxing. But in 2008, that doesn't seem to be the case any more. The well is running dry.
Indeed, it could be that Roy Jones Jr, who faces Wales' Joe Calzaghe at Madison Square Garden on Saturday, is the last in a long line of truly great black American fighters.
From Jack Johnson (the first black world heavyweight champion) to Henry Armstrong (the only man to hold world titles at the three different weights simultaneously) to Joe Louis (the most heavyweight world title defences in history) to Sugar Ray Robinson (the 'actual' greatest) to Ali (the most transcendental sportsman who ever lived) to Leonard, Hearns and Whitaker, African-Americans made the sport their own.
Bernard Hopkins lost to Joe Calzaghe in April
But you won't find many in most pound-for-pound top 10s today. Bernard Hopkins, American boxing's Ol' Man River, would certainly make an appearance. But he's 43.
In Beijing, America's boxers captured a single bronze in what was their worst performance at an Olympics in 60 years. So it would appear that not only is the well running dry, it's not likely to be replenished any time soon.
Scoop Jackson, writing on boxing for ESPN, says "boxing's problem" is one "America should be discussing and trying to fix". But this strikes me as a rather short-sighted view.
As Al Mitchell, former head coach of the USA Olympic boxing team and one of America's most respected amateur trainers, told me, "there are so many ways to get rich in the United States now, even for black people".
"When the Irish, the Jews and the Italians first came over, they all went to boxing," said Mitchell.
"But once they got into the system and learned there were other jobs and other ways to make money, they didn't do that any more. African-Americans are doing the same thing now.
"Here in America, even poor kids are going to college and saying, 'I don't want to get beaten up, it's not worth it'. In the wider scheme of things it's a good thing. But it's a bad thing for our sport."
Respected HBO boxing analyst Jim Lampley disagrees, asserting that "black American boxers are no longer as dominant because of the global rise of others".
But this would only make sense if any of the European heavyweight champions since Lennox Lewis' retirement had been outstanding. None of them have. Or if we had fighters of the calibre of Sugar Ray Leonard and Marvin Hagler currently plying their trade. We don't.
It's not that black Americans have given up on athletic pursuits, but you could argue they've just decided to take dominate different sports. Sports that have a higher profile and a better chance of financial reward. And far less pain.
So perhaps young black men who might have been boxers a generation ago are instead strutting their stuff in the NBA and NFL. Even Jones is a frustrated basketball player.
But not every young black American wants to be an athlete and presumably one of the main reasons for the falling numbers of top-class African-American boxers isn't that they're linemen or running backs in the NFL, or centres in the NBA. Rather, it's because they've taken Ali at his word.
They're electricians, mechanics, doctors, lawyers - pretty much everything an American can be in 2008. One of them is even President of the United States. And that's got to be better than fighting for a living.