At the 1904 Olympics in St. Louis, a man named George Eyser, German born, but representing the United States, won six medals (three gold, two silver, one bronze) in men’s gymnastics. Despite having lost a leg to a train (!) and competing with a wooden leg*
And, until 2008, he was the only Olympian to compete with an artificial limb. The second was a South African swimmer, cum marathoner who had a leg amputated after a car accident.