His cherry-red coffin, draped in an Islamic tapestry, was loaded into a hearse as a group of pallbearers that included former boxers Mike Tyson and Lennox Lewis and actor Will Smith left the funeral home in double file.
Ali’s nine children, wife, two ex-wives and other family members joined the funeral procession.
The 17-car motorcade set out for a Louisville cemetery on a 30km route via Muhammad Ali Boulevard that was also expected to take Ali’s body past the gym where he learned to box.
As the long line of black limousines went by, fans chanted like spectators at one of his fights, stood on cars, held up smartphones and signs, tossed flowers on to the bonnet of the hearse, and reached out to touch it.
Truckers honked their horns in salute. Others fell silent and looked on reverently as the champ went by.
Ali is to be laid to be rest under a headstone inscribed simply ‘Ali’, in a private graveside ceremony, followed in the afternoon by a grand memorial service attended by more than 15,000 people, including former president Bill Clinton and comedian Billy Crystal.
Ali, the most magnetic and controversial athlete of the 20th century, died last Friday aged 74 after a long battle with Parkinson’s disease. A traditional Muslim funeral service was held on Thursday, with an estimated 6,000 admirers arriving from all over the world.
Ali chose the cemetery, which is on the National Register of Historic Places, as his final resting place a decade ago. Its 130,000 graves represent a who’s who of Kentucky, including KFC founder Colonel Harland Sanders.
Family spokesman Bob Gunnell said the simple stone in Cave Hill Cemetery will be in keeping with Islamic tradition.
Ali himself decided years ago that when he died, the funeral would be open to ordinary fans, not just VIPs. As a result, thousands of free tickets were made available and were snatched up within an hour.
Louisville is accustomed to being in the limelight each May during the Kentucky Derby, but the sendoff for the three-time heavyweight champion and global ambassador for justice and understanding loomed as one of the city’s most historic events.
“We’ve all been dreading the passing of the champ, but at the same time we knew ultimately it would come,” mayor Greg Fischer said.
“It was selfish for us to think that we could hold on to him forever. Our job now, as a city, is to send him off with the class and dignity and respect that he deserves.”
Tyson was added at the last moment to the list of pallbearers. Mr Gunnell said Tyson was highly emotional upon learning of Ali’s death and was not sure if he could handle the memorial, but ended up catching a late flight.
President Barack Obama was unable to make the trip because of his daughter Malia’s secondary school graduation.