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About the Endangered Species Act

Updated June 3, 2026

Key Points

  • The purpose of the ESA is to protect and recover imperiled species and the ecosystems upon which they depend.

  • The U.S. Fish and Wildlife Service (Service) and the National Marine Fisheries Service (NMFS) administer the ESA.

  • Learn about what is Included in the ESA, and download a copy

Purpose of the Endangered Species Act

When Congress passed the Endangered Species Act in 1973, it recognized that our rich natural heritage is of “esthetic, ecological, educational, recreational, and scientific value to our nation and its people.” It further expressed concern that many of our nation’s native plants and animals were in danger of becoming extinct.

The purpose of the ESA is to protect and recover imperiled species and the ecosystems upon which they depend. Under the ESA, species may be listed as either endangered or threatened. “Endangered” means a species is in danger of extinction throughout all or a significant portion of its range. “Threatened” means a species is likely to become endangered within the foreseeable future. All species of plants and animals, except pest insects, are eligible for listing as endangered or threatened. For the purposes of the ESA, Congress defined species to include subspecies, varieties, and, for vertebrates, distinct population segments.

The U.S. Fish and Wildlife Service's Role

The U.S. Fish and Wildlife Service (Service) and the National Marine Fisheries Service (NMFS) administer the ESA. Our primary responsibilities are for terrestrial and freshwater organisms, while the responsibilities of NMFS are mainly marine wildlife such as whales and anadromous fish such as salmon.

As we work in partnership with others, our two major goals are to: 

  1. Protect species in need and then pursue their recovery
  2.  Conserve candidate species and at-risk species so that listing under the ESA is not necessary

History

Congress passed the Endangered Species Preservation Act in 1966, providing a means for listing native animal species as endangered and giving them limited protection. The departments of Interior, Agriculture, and Defense were to seek to protect listed species, and, insofar as consistent with their primary purposes, preserve the habitats of such species. The Act also authorized the Service to acquire land as habitat for endangered species. In 1969, Congress amended the Act to provide additional protection to species in danger of "worldwide extinction" by prohibiting their importation and subsequent sale in the U.S. This Act called for an international meeting to adopt a convention to conserve endangered species. One amendment to the Act changed its title to the Endangered Species Conservation Act.

A 1973 conference in Washington, D.C. led 80 nations to sign the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which monitors, and in some cases, restricts international commerce in plant and animal species believed to be harmed by trade.

Later that year, Congress passed the Endangered Species Act (ESA), which:

  • defined "endangered" and "threatened" [section 3];
  • made plants and all invertebrates eligible for protection [section 3];
  • applied broad "take" prohibitions to all endangered animal species and allowed the prohibitions to apply to threatened animal species by special regulation [section 9];
  • required federal agencies to use their authorities to conserve listed species and consult on "may affect" actions [section 7];
  • prohibited federal agencies from authorizing, funding, or carrying out any action that would jeopardize a listed species or destroy or modify its "critical habitat" [section 7];
  • made matching funds available to states with cooperative agreements [section 6];
  • provided funding authority for land acquisition for foreign species [section 8]; and
  • implemented CITES protection in the U.S. [section 8].

Congress enacted significant amendments in 1978, 1982, and 1988, while keeping the overall framework of the ESA essentially unchanged. The funding levels in the present ESA were authorized through Fiscal Year 1992. Congress has annually appropriated funds since that time.

Find Principal Amendments

Download a Copy of the ESA

The Endangered Species Act establishes protections for fish, wildlife, and plants that are listed as threatened or endangered; provides for adding species to and removing them from the list of threatened and endangered species, and for preparing and implementing plans for their recovery; provides for interagency cooperation to avoid take of listed species and for issuing permits for otherwise prohibited activities; provides for cooperation with States, including authorization of financial assistance; and implements the provisions of the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES). 

Date Enacted

Dec 28, 1973

Citation

16 U.S.C. 1531-1544

endangered-species-act.pdfPDF143.6 KBMay 3, 2024

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