What is climate history? How can it serve as a lens through which to view other historical questions? This roundtable identifies key themes in Gilded Age and Progressive Era climate history, and demonstrates that this era was pivotal for both scientific and cultural perceptions of climate. It also shows how climate history can illuminate other subjects, including histories of science, medicine, health, and race. Further, it considers present-day implications. This roundtable began as a session sponsored by the Society for Historians of the Gilded Age and Progressive Era at the 2024 Organization of American Historians annual meeting in New Orleans. What follows is a conversation based on that panel, a selected bibliography of scholarly sources, and a collection of primary sources for teaching climate history.