Donald Baxter MacMillan (1874-1970), American explorer, born in Provincetown, Massachusetts, and educated at Bowdoin College and Harvard University. He first explored (1908-9) the Arctic in the North Polar Expedition, led by the American explorer Robert Edwin Peary. MacMillan made 27 trips to the polar regions during the next 45 years. He led expeditions in Greenland, Labrador, and Baffin, Ellesmere, and Axel Heiberg islands, and he preserved rare samples of arctic vegetation and mineral deposits. In 1925 he directed a polar expedition in Greenland with the aid of U.S. Navy commander Richard Evelyn Byrd. For his explorations and scientific researches,MacMillan received many awards, including the special congressional medal (1944) and the Hubbard Gold Medal (1953) of the National Geographic Society. His writings include Four Years in the White North (1918), Etah and Beyond (1927), and How Peary Reached the Pole (1932).