Documenting bird behavior has been a central goal of the Cornell Lab of Ornithology since its inception. It was a major focus of the Lab's founders and, from the earliest days, played a crucial role in its outreach and educational missions. Naturally, technological abilities have evolved dramatically over the last century. The Lab has been a key agent in adopting and promoting, and in many cases developing, new technologies for the documentation of animal behavior and natural history. The culmination of this long history is the current Macaulay Library: a digital archive accessible to the public and containing the world's largest collection of animal sounds as well as a rapidly growing video library of animal behavior. We invite you to explore the timeline above to learn how the Macaulay Library came to be, and its central role in shaping the evolution of animal behavior study.