Karl Jordan (1861-1959) was an extraordinarily productive entomologist who influenced the development of systematics, entomology, and naturalists' theoretical framework as well as their practice. He has been a figure in existing accounts of the naturalist tradition between 1890 and 1940 that have defended the relative contribution of naturalists to the modern evolutionary synthesis. These accounts, while useful, have primarily examined the natural history of the period in view of how it led to developments in the 1930s and 40s, removing pre-Synthesis naturalists like Jordan from their research programs, institutional contexts, and disciplinary homes, for the sake of synthesis narratives. This dissertation redresses this picture by examining a naturalist, who, although often cited as important in the synthesis, is more accurately viewed as a man working on the problems of an earlier period. This study examines the specific problems that concerned Jordan, as well as the dynamic institutional, international, theoretical and methodological context of entomology and natural history during his lifetime. It focuses upon how the context in which natural history has been done changed greatly during Jordan's life time, and discusses the role of these changes in both placing naturalists on the defensive among an array of new disciplines and attitudes in science, and providing them with new tools and justifications for doing natural history. One of the primary intents of this study is to demonstrate the many different motives and conditions through which naturalists came to and worked in natural history. It argues that understanding this diversity within the views, methods, and priorities of naturalists is not only important to developing a more accurate understanding of the naturalist tradition, but to understanding the ramifications of the complexity in the naturalist tradition for the fate of certain research programs as well. / Graduation date: 2004