Sugar Ray Robinson vs Gene Fulmer Rocky Marciano vs Joe Walcott Joe Louis vs Max Schmeling Bob Foster vs Dick Tiger George Foreman vs Joe Frazier
Addie, your list is great, but you should factor in Patterson-Johansson II...for both devastation AND historical implications.
I would add in Curry-McCrory and Duran-Lampkin. They meet the criteria in devastation obviously but historical also. Curry-McCrory was a unification and the Duran-Lampkin added to the Duran mystique with the "if I was in shape he would have been sent to the morgue instead of the hospital" tagline. I'm sure there are many more, but to get that "historical" reference down can be a bit daunting. Perhaps Carbajal-Gonzalez I also. I believe that was a unification if memory serves me and the KO was intense. Scartissue