Muhammad Ali was born Cassius Marcellus Clay on January 17th, 1942 in Louisville, Kentucky.  One day when he was 12 years old he was attending an event that was at the now Spalding University in Louisville, Kentucky. He rode his bicycle there, but when he went to go home he saw that his bike had been stolen. He was so angry that he told police officer Joe Martin that he wanted to beat up the person who stole his bike. Officer Martin calmed him down, and asked him if he wanted to box at the boxing gym that officer Martin helped to run. The young Cassius Clay said he did, and as a result the legend of Muhammad Ali was born.
"Float like a butterfly, and sting like a bee. Your hands can't hit what your eyes can't see." Muhammad Ali was by far the quickest, and the most quick witted heavyweight champion of all time.

Here is Muhammad Ali beating the then invincible Sonny Liston on February 25th, 1964 in Miami Beach Florida to win his first heavyweight championship of the world at the age of 22.
Here is Muhammad Ali when he was 12 years old.
Here is Muhammad Ali throwing an overhand right in his third and final fight with Joe Frazier in 1975. This was Ali's last great fight, and it was known as the "Thrilla in Manilla." Ali again proved what great boxing skill, willpower, and mental toughness that he had. Frazier could not come out for the 15th round. and Ali won with a TKO. Ali beat Frazier 2 out of  the 3 times that he fought him.
Muhammad Ali won an Olympic gold medal as the light heavyweight champion in the Rome Olympics in 1960.
Here is Muhammad Ali in 1972 fighting Jerry Quarry in Las Vegas, Nevada. Ali toyed and played with Quarry for a while, as he did with many of his opponents. Ali won on a TKO in the 6th round.
Muhammad Ali was a master of psychology.  He would beat his opponents both inside, and outside of the ring. In his later years his mental toughness played a great factor in many of his fights. There was no one stronger mentally then Muhammad Ali.
Here is Muhammad Ali humbling another opponent. Ali was famous for his lightning fast hands and feet, and his ability to entertain the crowd who came to watch his fights.
In 1967 Muhammad Ali refused to enter the military draft and go to Vietnam, which caused a great controversy at the time. As a result he was stripped of his heavyweight title, and banned from boxing for 3 and a half years until 1970 when the U.S. supreme court dismissed his case, and granted him the right to fight again. Despite losing 3 and a half years that were in the prime of his career, Ali came back to win the heavyweight championship of the world for the second time by beating George Foreman in 1974 .
Here is Muhammad Ali lighting the Olympic torch to initiate the start of the 1996 summer Olympics.
Here is Muhammad Ali today. He has parkinsons disease, but he is still as quick witted and as intelligent as he ever was.  Muhammad Ali has had parkinsons disease since the day he was born, being a boxer did not cause the disease. Boxing may have made the onset of his parkinsons disease come sooner then it normally would have, but Muhammad Ali would have had parkinsons disease even if he had not been a boxer. Muhammad Ali was not only a great athlete, but he is a great human being as well. He is known for being a great humanitarian, and is beloved the world over for his kindness, and for the compassion that he has for other people. 
Here is Muhammad Ali returning to his corner after knocking out George Foreman in the 8th round on Oct. 30th, 1974 . Ali won back his heavyweight championship title in this fight known as the "Rumble in the Jungle."  It was the most highly watched event in sports history, and it was Ali's greatest fight! 
Muhammad Ali fought Kenny Norton twice in 1973. Ali lost the first fight, but he came back in September of that same year and he beat Norton. Ali later fought and beat Norton again in 1976.