The taxidermists who mounted specimens and created educational exhibits for America’s natural history museums, zoos, and aquaria of the late-nineteenth and early-twentieth centuries were also among the first to become aware of the devastating effects of careless human interaction with the natural world. Witnessing firsthand the decimation caused by hide-hunters, commercial feather collectors, whalers, big game hunters, and poachers, these museum men recognized the existential threat to critically endangered species and the urgent need to protect them. The compelling exhibits they created, as well as the field work, popular writing, and lobbying they undertook, established a vital leadership role in the early conservation movement for American natural history museums, a role that persists to this day. Through their individual research expeditions and collective efforts to arouse demand for environmental protections, this remarkable cohort, including William T. Hornaday, Carl E. Akeley, and their lesser known colleagues Frederic A. Lucas, Charles H. Townsend, and Frederic S. Webster, created our popular understanding of the animal world and its fragile habitats. For generations of museum visitors, they turned the glass of an exhibition case into a window on nature—and a mirror in which to reflect on our responsibility for its conservation.