Eighty-five pound Cassius Marcellus Clay, Jr., later known as Muhammad Ali, is shown posing at twelve, prior to his amateur ring debut in 1954, a three minute, three round split decision over another novice named Ronnie O'Keefe, in Louisville, Kentucky.

Portrait of Cassius Clay, later known as Muhammad Ali, training during the sixties.

Cassius Clay, later known as Muhammad Ali, poses as he trains for his upcoming Archie Moore fight November 1962 in Los Angeles.

Young heavyweight boxer Cassius Clay points to a sign he wrote on a chalk board in his dressing room before his fight against Archie Moore in Los Angeles, Nov. 15, 1962, predicting he'd knock Moore out in the fourth round, which he went on to do.

During a visit to the training room of the boxer in Miami, the Beatles were acting as if they were knocked out by the American boxer Muhammad Ali, April 22, 1964.

Sonny Liston lies out for the count after being KO'd in the first round of his return title fight by world heavyweight champion Muhammad Ali, Lewiston, Maine, May 25, 1965.

Boxer Muhammad Ali in training for a match against Brian London, August 1966.

American heavyweight boxing champion Muhammad Ali, circa 1970. The man in front of him is wearing a t-shirt printed with Ali's motto 'Float like a butterfly, sting like a bee'.

Muhammad Ali gives kids autographs to young fans, Miami, Florida, 1970.

American heavyweight boxing champion Muhammad Ali covers his eyes with his hand during a training session at Chris Dundee's 5th Street gym, Miami Beach, 1971.

American boxer Muhammad Ali (left) taunts rival boxer Joe Frazier at Frazier's training headquarters, Philadelphia, Pennsylvania, early 1971. The two men fought for the World Heavyweight Title on March 8, 1971--Frazier won.

Muhammad Ali lands a left hook to Joe Frazier during a bout at Madison Square Garden, March 8, 1971 in New York, New York.

The first contest between Muhammad Ali and Joe Frazier matched an unbeaten former heavyweight champion against the unbeaten current champ on March 8, 1971. A crowd of 20,455 filled New York City's Madison Square Garden and 300 million watched across the world on closed-circuit TV.

Boxer Muhammad Ali shadowboxes in a sitting room.

Muhammad Ali, right, winces as Ken Norton hits him with a left to the head during their re-match at the Forum in Inglewood, Calif., Sept. 10, 1973.

A general view of "The Match of the Century" between the former world heavyweight boxing champion the American Muhammad Ali, right, and his compatriot and titleholder George Foreman, left. Ali won and got back his title Oct. 30, 1974 in Kinshasa, Congo.

Image shows American boxer Muhammad Ali, right, and his opponent, American boxer Earnie Shavers, during the 1st round of their Heavyweight Title fight at Madison Square Garden, Sep. 29, 1977.

A picture taken in Moscow on September 16, 1978, of the world heavyweight boxing champion Muhammad Ali. left, during the match he won against his compatriot Leon Spinks.

Muhammad Ali yawns while babysitting two of his daughters by wife Veronica Porche, 9-month-old Laila, left, and 2-year-old Hana, right, in London, Dec. 19, 1978.

Muhammad Ali and his third wife, Veronica Porsche, are photographed in their Los Angeles home before his fight with Larry Holmes which took place in Las Vegas, Oct. 2, 1980.

Heavyweight boxer Muhammad Ali with his daughters Laila (9 months) and Hanna (2 years 5 months) at Grosvenor House, Dec. 19, 1978.

Joe Frazier, George Foreman, and Muhammad Ali pose for a photo in the ring, Sept. 1, 1989.

Former heavyweight boxing champion Muhammad Ali whispers to American hostage Richard Illif, Roswell, Georgia, after they arrived on a flight from Baghdad in Amman, Jordan, Dec. 2, 1990. The American were released after Muhammad Ali met Iraqi President Saddam Hussein.

Muhammad Ali participates in a religious ceremony for the holy month of Ramadan in the Royal Palace in Rabat, Morocco, Jan. 15, 2001.

US former world heavyweight boxing champion Muhammad Ali, left, jokes with US actor Will Smith, right, who portrays him in new film "Ali," at the movie's premiere in Hollywood, Dec. 12, 2001.

Muhammad Ali lights the first Olympic torch for the Salt Lake 2002 Olympic Winter Games at Centennial Olympic Park in Atlanta, Dec. 4, 2001.

Muhammad Ali is kissed by his wife Yolanda during a book presentation at the Frankfurt Book Fair in Germany, 2003.

Laila Ali poses with her father, Muhammad Ali, after her 10 round WBC/WIBA Super Middleweight title bout with Erin Toughill at the MCI Center in Washington, DC, June 11, 2005.

Former boxer Muhammad Ali attends the 4th Annual Life Changing Lives Gala honoring Muhammad Ali at City National Grove of Anaheim on Sept. 11, 2011 in Anaheim, Calif.

Muhammad Ali attends the Celebrity Fight Night XIX at JW Marriott Desert Ridge Resort & Spa in Phoenix, Ariz., March 23, 2013

From left, John Wooten, Jim Brown, Bill Russell, and Bobby Mitchell stand behind Muhammad Ali before the start of the Ali Humanitarian Awards ceremony, Sept. 27, 2014 at the Louisville Marriott Downtown in Louisville, Kentucky. The four were participants of the 'Ali Summit' in 1967, and Brown will be receiving the Ali Humanitarian Lifetime Achievement Award.

Boxing great Muhammad Ali, center, is cheered by the audience as his wife Lonnie Ali, left, and his sister in law Marilyn Williams look on, as he is awarded the Grawemeyer Spirit Award at The Louisville Palace Theater in Louisville, Kentucky, Sept. 17, 2015.