Robert Peary was an American explorer who made several expeditions to the Arctic, exploring much of it by dog sled, but he's most famous for his claim to have been the first person to reach the geographic North Pole. Peary said he reached the pole on April 6, 1909, but Frederick Cook, an American doctor who had accompanied Peary on previous expeditions, claimed to have reached the pole a year earlier. A 1911 congressional inquiry resulted in Peary being declared the first man to reach the North Pole, but doubts remain, even today. Peary differed in style from most polar explorers; he studied Inuit survival techniques and built igloos, used sled dogs and dressed in furs. Despite his preparations, he still lost eight toes to the Arctic’s freezing temperatures.