Yesterday was the 40th anniversary of Ali-Frazier 1 in 1971. The retrospectives reveal a number of important things. First, most Americans have forgotten how polarizing Ali was back in the late 60s/early 70s because of his conversion to the Nation of Islam and his opposition to the Vietnam War. The anti-war movement and the counterculture embraced Ali while many working-class white supporters of the war backed Frazier because they viewed Ali as an unpatriotic draft-dodger.
Furthermore, Ali-Frazier 1 was one of the biggest sporting events of the 20th century and engaged people who were not sports fans or boxing fans. Today, boxing has almost disappeared from the sports landscape. The last fight that casual fans may have been interested was Tyson-Spinks in 1988 or maybe Tyson-Holyfield II in 1997.
Check out an old HBO documentary, Ali-Frazier: One Nation Divisible, for more.