Edward W. Nelson served as a naturalist and collector in Alaska for Spencer F. Baird and the Smithsonian Institute during the late 1870’s. While there he amassed an immense knowledge of the wildlife and people. Moving further south in the last decade of the nineteenth century, he worked in California and Central America with the Bureau of Biological Survey. While in Mexico (1892-1906) with Edward Alphonso Goldman, he conducted one of the most comprehensive biological explorations of any single region. In 1916 he became chief of the U.S. Biological Survey, replacing Henry Henshaw. He was responsible for the implementation of the Migratory Bird Treaty Act of 1918.