Well Ali wasn't the greatest fighter of all-time in boxing, everyone knows that, including Ali himself, who said Ray Robinson was the greatest fighter of all time. Ali may be top 10. The reason he has such a legacy, was the era in which he fought, the Muslim stand, in a time Malcolm X was assasinated, changing his name from that given to him by his 'slave masters', in a time when Luther King was big, in addition to winning the gold medal at the Olympic and throwing it away, the stand against the Vietnam war and fighting in a golden age in the heavyweights at the time (Frazier, Foreman etc). It's the entire story, not that he was simply the best fighter. You can't create that, it just has to happen, external factors in life and your reaction to them.