Boxer, being the biggest and strongest animal on the farm, adopted the maxim, "I will work harder!" soon after the Rebellion. He was keen to do his best for the good of all and was motivated by the freedom the animals experienced at the time. His commitment is clearly illustrated in the following excerpt from chapter three:
Boxer was the admiration of everybody. He had been a hard worker even in Jones's time, but now he seemed more like three horses than one; there were days when the entire work of the farm seemed to rest on his mighty shoulders. From morning to night he was pushing and pulling, always at the spot where the work was hardest. He had made an arrangement with one of the cockerels to call him in the mornings half an hour earlier than anyone else, and would put in some volunteer labour at whatever seemed to be most needed, before the regular day's work began. His answer to every problem, every setback, was "I will work harder!"—which he had adopted as his personal motto.
It was after Snowball's expulsion by Napoleon that Boxer really proved his mettle. Three Sundays after Snowball's removal, Napoleon declared that the plans for the building of a windmill had actually been his idea and that they would start erecting it. The construction, however, presented a number of problems since the animals had to drag huge stones from the bottom of the quarry to the top, where they would then be toppled over the edge to shatter into manageable pieces below.
This was a slow and very difficult process, but Boxer inspired everyone with his hard work. Whenever Boxer encountered a problem, including when a boulder was ready to slip, he would use every ounce of his strength to stop it from rolling back into the quarry, as revealed in chapter 6:
Nothing could have been achieved without Boxer, whose strength seemed equal to that of all the rest of the animals put together. When the boulder began to slip and the animals cried out in despair at finding themselves dragged down the hill, it was always Boxer who strained himself against the rope and brought the boulder to a stop. To see him toiling up the slope inch by inch, his breath coming fast, the tips of his hoofs clawing at the ground, and his great sides matted with sweat, filled everyone with admiration. Clover warned him sometimes to be careful not to overstrain himself, but Boxer would never listen to her. His two slogans, "I will work harder" and "Napoleon is always right," seemed to him a sufficient answer to all problems.
Later in the novel, Boxer gave specific instructions so he could do even more work:
He had made arrangements with the cockerel to call him three-quarters of an hour earlier in the mornings instead of half an hour. And in his spare moments, of which there were not many nowadays, he would go alone to the quarry, collect a load of broken stone, and drag it down to the site of the windmill unassisted.
He was even prepared to come out at nights during the harvest moon to do extra labor.
Unfortunately, the half-built structure was destroyed during a terrible storm and the animals had to start all over again, but Boxer was up to the task. After the animals' exhausting efforts finished by autumn, the windmill was finally finished, but tragedy struck again when Frederick and his men blew it to pieces. Once again, it had to be rebuilt and, once again, Boxer proved his mettle and dedication.
Boxer worked so hard that it eventually affected his health. He suffered a split hoof, which took a long time to heal. We read in chapter nine, however, that he refused to give up:
Boxer refused to take even a day off work, and made it a point of honour not to let it be seen that he was in pain. In the evenings he would admit privately to Clover that the hoof troubled him a great deal. Clover treated the hoof with poultices of herbs which she prepared by chewing them, and both she and Benjamin urged Boxer to work less hard. "A horse's lungs do not last for ever," she said to him. But Boxer would not listen. He had, he said, only one real ambition left—to see the windmill well under way before he reached the age for retirement.
Once Boxer's hoof was healed, he worked harder than ever. He had, however, lost much of his vitality and looked weaker than ever before, but continued working, even though Clover and Benjamin expressed concern and asked him to look after his health. He only repeated his motto, "I will work harder!" and continued to work.
Boxer's hard work was never really rewarded. We read in chapter nine that he fell desperately ill and was lying on his side with blood trickling from his mouth. The poor beast believed that he would be able to retire and then live a life of comfort and relaxation. It was not to be. The pigs sold him to the knacker and bought a case of whiskey with the proceeds. Squealer later spun a story about how bravely Boxer had passed away, stating his last words were to encourage the other animals by whispering in his final breath:
"'Forward in the name of the Rebellion. Long live Animal Farm! Long live Comrade Napoleon! Napoleon is always right.' Those were his very last words, comrades."