Sullivan, Jeffries, Wills, Peter Jackson, Langford, Mcvey/Mccea & Jeannette I really struggle with how to place these guys in a historical ranking, so adding any other thoughts are appreciated
James J Jeffries John L Sullivan Peter Jackson Sam Langford Harry Wills (Joe Jeannette) Sam McVea I think Jeffries was a true ATG, with the best title reign pre-Joe Louis. The division at that point had a lot of smaller fighters, but I think was strong in a more P4P sense. Sullivan is probably the hardest to rate. Super dominant in a weak era, with not a ton of information. I bump up Peter Jackson and Harry Wills, as I think they both almost certainly should have been champion, but I'm not actually convinced either was actually that special ability wise. Both had very good runs though. I will say, what I've managed to find from exhibitions between Slavin and Mitchell suggest that Mitchel (who was probably past his best, while Slavin was around his), seemd capable of holding his own against his bigger opponent. If anyone has more on their exhibitions I'd love to see it. H2H I'd put Langford ahead of Jackson, and I'm not sure Wills is really much ahead, if at all Jeannette and McVey. P4P Langford is obviously way ahead.
From a ranking mattdonnellon did. James J Jeffries Sam Langford Peter Jackson Harry Wills Joe Jeannette - - - - John L Sullivan Sam McVea (I'm not entirely sure if they are ranked in order, or if the first lot were tier 1, and the second tier 2)