In my opinion, the toughest of all was Joe "Iron Man" Grimm.
He virtually had no skills to speak of, and his record of 6-91-9 (4) pretty much shows that is true. Though a middleweight naturally, he fought some of the hardest hitting heavyweights of the time, and out of 113 fights he was only stopped 5 times. His career went from 1900-1913, losing four of the five kayo losses in the last five years of his career.
He went the distance with such men as Joe Gans, Luther McCarty, Jack Fitzgerald, Battling Levinsky, Al Kaufman, Jack Johnson, Jack Blackburn, Dixie Kid, Peter Maher, Dave Holly, Joe Walcott, Bob Fitzsimmons, Philadelphia Jack O'Brien, and George Cole.
Despite the ridiculous odds, none of those listed were able to knock him out, either winning decisions or sported no-contests against a man who was described as a "human punching bag".
Jack Johnson knocked Grimm down "more than a dozen times" times in six rounds. Joe Gans bet $100 bucks he could knock Grimm out in less than six rounds, it didn't happen. It was reported in an exhibition bout against Tommy Burns, Grimm hit the canvas a dozen times himself in three rounds, but the Canadian couldn't knock him out.
The only men to ever stop a "prime" Joe Grimm was Sam McVea (KO12th) and Sailor Burke, though it is argued that Grimm took a dive to make huge money off the bets, considering he was almost impossible to knock out. Jack Blackburn, who fought Grimm three times in a row, almost came close to stopping him in their first encounter in the 5th, but Grimm somehow or another managed to keep Blackburn off enough and actually hurt him at times, to many people's surprise.
Name another 'tough man' in boxing
