Wiessner was a 39-year-old German rock climber who had achieved a huge number of climbing routes in the Alps, some of them outstanding first ascents. He was an astute businessman in the chemical industry and a visit to America in 1929 drew him into spending more, and then nearly all, his time there. In 1932 he joined an expedition to Nanga Parbat led by Willy Merkl. From their high point at Wiessner spotted K2 away and the mountain became an obsession for him. Back in the United States Wiessner made friends with many influential and rich people and he introduced skiing and rock climbing techniques of a higher standard than those practised at that time in America. In 1935 he became a U.S. citizen and the next year he and Bill House became celebrated as the first people to climb Mount Waddington in Canada, a mountain on which there had previously been sixteen unsuccessful attempts. By 1938 he had become the pre-eminent American climber and, having been on Nanga Parbat, the only one with experience on an eight-thousand-metre peak. He seemed the obvious choice to lead the 1938 expedition for which he had led the successful attempts to secure funding. As it turned out he had prior commitments in 1938 but he was available for 1939.