PHOENIX (CBSNewYork/CBS News/AP) — Tributes to Muhammad Ali rolled in from around the world Saturday, just hours after his death.

“The Greatest” had been hospitalized for respiratory problems Thursday, and news spread that this illness was serious. Late Friday, his family confirmed that he had died.

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Mayor Bill de Blasio and First Lady Chirlane McCray announced the city would project a tribute in lights to the champion Saturday evening. The event was held at the intersection of West 125th Street and St. Nicholas Avenue in Harlem from 8:20 p.m. to midnight.

“Muhammad Ali was a champion, activist and the self-proclaimed Greatest,” de Blasio said. “Throughout his life he lived up to that title again and again. Tonight, NYC comes together in the heart of Harlem to pay tribute to the man who never backed down from a fight in or outside the ring.”

Standing outside Madison Square Garden — where Ali took on Joe Frazier in what became the “Fight of the Century” in 1971 — New Yorkers paid respects to Ali not only as an athlete, but for who he was outside of the ring.

“He was a man who stood up for his rights, who stood up for people and stood up for the downtrodden,” one man told 1010 WINS’ Roger Stern.

“He was legendary, he was one of the greatest in his own words,” another New Yorker told WCBS 880’s Sophia Hall. 

Speaking in Harlem, Rev. Al Sharpton said he first met Ali when he was only 19 years old, WCBS 880’s Sophia Hall reported.

“One of the few memories I had of my father was that my father took me to a closed circuit dinner to see Ali fight Liston,” Sharpton said. “My father had been a boxer. I was about nine years old.”

Sharpton also praised his long-time friend for having the courage not to go to Vietnam, even though it meant losing his heavyweight title and risking jail, Stern reported.

“He was the greatest of all time, in his sacrifice, in his dedication and is commitment,” Sharpton said. “He believed in himself and he became a champion like we never saw before and will never see again.”

Sharpton said he also planned to be at Ali’s funeral in Louisville, Kentucky next week. 

Civil rights leader the Rev. Jesse Jackson, a longtime friend of Ali, says the boxer’s impact extended far beyond the ring. He called the boxer a “social transformer” who used his fame to attack injustice during the civil rights struggle.

“From Texas across, from Florida up to Maryland, we couldn’t use a single public toilet,” Jackson said. “We couldn’t use the libraries or the theaters or sit in the public parks. Ali identified with that struggle, used his person and his fame to illuminate that state of moral darkness in our country.”

Jackson said he believed that decades later Ali reveled in being celebrated by those who once rejected him for his outspoken activism.

“That he had come full circle from being reviled to being revered, from being dismissed to being embraced,” Jackson said. “I think he found a certain joy in that.”

Madison Square Garden paid tribute to Ali with a special billboard displaying a photo of the three-time heavyweight champion with the words, “The Greatest,” WCBS 880’s Stephanie Colombini reported.

Reaction came in from around the world of sports, entertainment and politics. President Bill Clinton who awarded Ali the Presidential Citizens Medal, mourned the death of the three-time heavyweight champion.

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“Hillary and I are saddened by the passing of Muhammad Ali,” Clinton said in a statement. “From the day he claimed the Olympic gold medal in 1960, boxing fans across the world knew they were seeing a blend of beauty and grace, speed and strength that may never be matched again.”

One of Britain’s top television interviewers, Michael Parkinson, had four verbal bouts opposite Ali — and described the fighter Saturday as the most memorable guest of his 40-year career.

Parkinson told the BBC that Ali’s family recently asked him to provide audio recordings of all four interviews, so that Ali would listen to the decades-old discussions, which produced myriad clips highlighting his quick wit and indignation over racial discrimination. 

“He was the most extraordinary man I ever met. He could be threatening. When I questioned him about his views on race, there was real anger in his response — and I looked into the eyes of somebody I thought might fell me in one blow,” Parkinson said.

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“That was just one aspect of a multi-faceted man and I loved him in a sense. When you look at all the thousands I’ve interviewed a few stand out. And he was the one that stands out most of all.”

British author J.K. Rowling, who penned the Harry Potter series, took to Twitter to pay her respects, shedding light on a powerful quote from the boxing great himself:

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Several boxers, including George Foreman, who lost to Ali in the legendary Rumble In The Jungle,” also paid their respects to the boxing great.

“Muhammad Ali was a friend of the people he was a fighter for the people,” legendary boxing promoter Don King told CBS2. “I love Muhammad Ali. He was a friend for life and he will never die — his spirit will go on forever.”

Ali’s daughter, Hana, tweeted “our father was a “Humble Mountain!” And now he has gone home to God. God bless you daddy. YOU ARE THE LOVE OF MY LIFE!”

The head of the Nelson Mandela Foundation says the Nobel Peace Prize winner and former South African president called Muhammad Ali his boxing hero.

“Madiba had great respect for his legacy and spoke with admiration of Ali’s achievements,” Sello Hatang, the foundation’s CEO, said in a statement Saturday.

A photograph of Ali and Mandela together sat next to the former president’s desk at his foundation, the statement said, and Mandela’s favorite book at the office in his later years was an autographed copy of the Ali biography “Greatest of All Time.”

The statement included a comment Mandela made at an event in Washington in 1990: “There is one regret I have had throughout my life: that I never became the boxing heavyweight champion of the world.” 

Irish President Michael D. Higgins says the people of Ireland have awoken to news of Ali’s passing “with the greatest sadness.”

Ireland’s ceremonial head of state called Ali a man of “wit, grace and beauty” who “brought his message of freedom and respect for people of all races to all the continents of the world.”

Referring to Ali’s long fight against Parkinson’s disease, Higgins said the boxer inspired untold millions by displaying “courage in the face of great difficulties. He was intent on communicating right to the very end.”

Ireland, a nation that long has punched above its weight in the ring, has harbored a love for Ali since his July 1972 fight in Dublin’s Croke Park stadium against Al “Blue” Lewis. The western town of Ennis in 2009 named him its first-ever “freeman,” an honor Ali accepted in person — nearly 150 years after Ali’s great-great-grandfather Abe O’Grady emigrated from Ennis to America.

British boxer Amir Khan has paid tribute to Ali in a video message from his family’s native Rawalpindi in Pakistan.

“Muhammad Ali was my hero. I’m so happy that I got to meet the guy,” said Khan, who admired every aspect of Ali’s game: his unique skillset, his confidence and his faith.

“He was one of the only fighters who predicted what round he was going to win and then knock his opponent out in that round. That’s something you hardly ever see.”

“He used to beat opponents with his mouth before he ever got into the boxing ring. He would win the fight before the fight even happened.”

Khan, a British-born Muslim, said Ali showed courage for converting to Islam in 1960s America. “What he believed in, he did.”

Tonight, 48 Hours will present a special “Muhammad Ali: Remembering a Legend” at 9 p.m. on CBS2.

A memorial service is scheduled for 10 a.m. in Louisville, Kentucky, Ali’s hometown.

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