I heard that it restricted his movement and affected his ability to punch properly, what do you make of it?
About six weeks before the fight Jackson suffered a sprained ankle in a dog cart accident. He was laid up in bed for a couple of days, and on crutches for a couple of weeks after that. Although it undoubtedly interfered with his training, he seemed pretty much recovered by fight time, but observers noticed that his ankle was still slightly swollen when he entered the ring. By the end of 61 rounds, the swelling was worse, and he was seen to be limping. Feels like Jackson would probably have been okay in a limited rounds bout, but the ankle inevitably weakened under him in a marathon like this one.
Found this account of the fight online: Jackson showed all of his old-time cleverness, and his ankle, about which so much has been said and written since the day he was thrown from his cart, gave him no apparent trouble. There was not the slightest halt in the movements of his feet, as a sparrer he proved himself fully the equal of his game antagonist. In one respect, however, Jackson proved a disappointment to his friends. It is evident that he has lost none of his cleverness as before stated, but physically, it must be admitted, he has retrograded. His blows were lacking in steam, and were light compared with those before which Godfrey went down in such short order. He has lost none of his generalship, however, and that, perhaps, more than any other reason, saved him last night from defeat. His life, since coming to California 3 years ago, has been a continuous record of 'fast-living', and that has made him what he showed himself to be - a man who is on the decline as a pugilist, so far as strength is concerned. Corbett showed himself to be an exceptionally clever Boxer, but those who watched him went away with a lurking suspicion that this far outshone his ability as a 'Fighter'. Those who have seen both, think that with either Sullivan or Slavin, he would be badly handicapped, and would find it hard to hold his own?' - 'San Francisco Call', 1891
The rib injury is what imobilized Jackson and basically ended the fight somewhere in the early 20s. Aside from one round where Corbett broke Jacksons ribs Jackson had dominated the fight. While this fight lasted 61 rounds about 2/3s of it was both fighters basically awkwardly posturing for the ref to stop it. After the exchange that imobilized Jackson both fighters were done. However bad shape Jackson was in it wasn't bad enough for Corbett to take advantage of it again.
