All translations are from German unless otherwise indicated. The children of Franz Boas, Helene Boas Yampolsky and Ernst Boas, translated many of the letters in the Boas Papers and in the Boas Family Papers. When these translations from the American Philosophical Society are cited, the translator is not indicated. Indeed, often the translator is not known. For new translations undertaken for this work, the following abbreviations for translators are used: Esther Muench (EM), Ludger Müller-Wille (LMW), and Rosemary Lévy Zumwalt (RLZ).