At the end of World War I large areas at the top and bottom of the globe were still vast, cold mysteries. Into these blanks on the map explorers flew, urged on by their sponsors to achieve "firsts," by their governments to claim new land, and by a public fascinated with moving pictures and radio broadcasts. In March 1926 Wilkins and Byrd, along with veteran explorer Roald Amundsen, were locked in a race to the North Pole. A year later, while Amundsen...