Federal protection of endangered species dates back to the Lacey Act of 1900, when, in response to growing public concern about the pending extinction of the passenger pigeon, Congress passed the first wildlife law. The next 70 years saw a groundswell of public awareness of environmental problems and support for wildlife conservation, which initiated political activism. Congress passed the Endangered Species Preservation Act of 1966, the first piece of comprehensive endangered species legislation. It was under the 1966 Endangered Species Preservation Act that the very first list of threatened and endangered species was compiled. The Endangered Species Conservation Act of 1969 improved upon the 1966 Act, providing better protection to species habitats and considered species in danger of worldwide extinction. Still not satisfied with the protections the 1969 Act provided domestic species, Congress passed the Endangered Species Act of 1973 (ESA). The ESA combined and strengthened its predecessors, to become the primary means for federal agencies to protect threatened and endangered species and their habitats.
Influenced by the impending extinction of the passenger pigeon, a once plentiful bird, Congress passes the Lacey Act to help states protect resident species by making it unlawful to transport illegally taken wildlife across state lines.
President Theodore Roosevelt establishes the first Federal Bird Reservation on Pelican Island, Florida, to protect the brown pelican and other water birds decimated by plume-hunters for the fashion industry. Pelican Island was later re-designated as a National Wildlife Refuge in 1942.
The U.S. and Great Britain, on behalf of Canada, sign a treaty to protect birds that migrate between the U.S. and Canada, recognizing them as international resources. On July 3, 1918, the U.S. passed the Migratory Bird Treaty Act to implement the treaty
Congress passes the Federal Aid in Wildlife Restoration Act, commonly called the Pittman-Robertson Act, providing a funding mechanism for states to acquire wildlife habitat through a federal tax on hunting equipment.
The Bureau of Fisheries and Biological Survey are moved to the Department of the Interior, and, in the following year, are combined to create the U.S. Fish and Wildlife Service (Service).
Passage of the Bald Eagle Protection Act makes it a federal offense to take or possess the species, including its parts or nests except as permitted for scientific, educational, or depredation purposes.
The Committee on Rare and Endangered Wildlife Species publishes Rare and Endangered Fish and Wildlife of the United States.
The Endangered Species Preservation Act of 1966, the first federal endangered species legislation, authorizes the Secretary of the Interior to list native species of fish and wildlife as endangered and to acquire endangered species habitat for inclusion in the newly established National Wildlife Refuge System.
The first endangered species – all vertebrates – are listed under the Endangered Species Preservation Act of 1966: 14 mammals, 36 birds, 3 reptiles, 3 amphibians, and 22 fishes.
The Endangered Species Conservation Act of 1969 amends and renames the Endangered Species Preservation Act of 1966 to extend protection to animals "threatened with worldwide extinction."
Nevada enacts the first state endangered species act, which provides some protection for animals and explicit exceptions to protect agricultural interests.
President Nixon signs the National Environmental Policy Act, requiring federal agencies to assess the environmental impacts of their actions in the decision making process.