1903: President Theodore Roosevelt establishes the first National Wildlife Refuge at Pelican Island, Florida, to protect wood storks, brown pelicans, and other dwindling water birds. (Today, national wildlife refuges support nearly 300 endangered and threatened plant and animal species.)

1914: The passenger pigeon, once the most abundant bird in North America, and perhaps the world, becomes extinct, joining a long list of extinct species that include the ivory-billed woodpecker, great auk, health hen, Carolina parakeet, and others.

1916: The United States and Great Britain (on behalf of Canada) adopted a uniform system of protection for certain species of birds that migrate between the United States and Canada. On July 3, 1918, the United States passed the Migratory Bird Treaty Act to implement the treaty.

1944: The whooping crane population reaches its lowest population level, with only 21 birds remaining.

1962: Rachel Carson’s Silent Spring warns of impacts on wildlife and people from unregulated pesticide use.

1966: Endangered Species Preservation Act of 1966 authorizes land acquisition to conserve “selected species of native fish and wildlife.”

1967: The first list of 78 endangered species is published.

1969: Endangered Species Conservation Act of 1969 expands on the 1966 act, authorizing the compilation of a list of animals “threatened with worldwide extinction” and prohibits their importation without a permit. Crustaceans and mollusks are included for protection, along with mammals, fish, birds, and amphibians.

1970: The peregrine falcon is listed as endangered.

1972: The Environmental Protection Agency outlaws DDT as a pesticide because of its potential danger to people. The chemical is linked to the thinning of eggshells of bald eagles and peregrine falcons, reducing hatching success and contributing to their endangered status.

1973: Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) - 80 nations sign this treaty to protect designated plant and animal species by regulating or prohibiting international trade in certain taxa except by permit.

1973: Endangered Species Act of 1973 supersedes earlier endangered species acts, broadens and strengthens protection for all plant as well as animal species listed by the U.S. as threatened or endangered, prohibits take and trade without a permit, requires Federal agencies to avoid jeopardizing their survival, and requires actions to promote species recovery. The ESA defines an “endangered species” as any species in danger of extinction throughout all or a significant portion of its range.” A “threatened” species is one likely to become endangered within the foreseeable future throughout all or a significant portion of its range.” The ESA has become one of the most effective tools in the continuing effort to protect imperiled species and their habitats in the U.S.

1975: The Smithsonian Institution, which was directed by the ESA to identify plant species in need of ESA protection, produces a report recommending more than 3,000 plant species for possible listing as threatened or endangered.

1977: First four plant species are listed as endangered – the San Clemente Island Indian paintbrush, San Clemente Island larkspur, San Clemente Island broom, and San Clemente Island bush-mallow.

1978: Endangered Species Act Amendments of 1978 formalize the process under section 7 of the ESA by which Federal agencies consult with the FWS to ensure that their actions are not likely to jeopardize the survival of listed species or adversely modify designated “critical habitat.” Further, the amendments establish an Endangered Species Committee that may allow exemptions to this provision under special circumstances.

1978: Endangered Species Committee exempts the Grayrocks reservoir project in Wyoming from section 7 of the ESA but denies an exemption for Tellico Dam project in Tennessee.

1979: In September, Congress passes an appropriations bill that includes an exemption for the Tellico Dam project, flooding critical habitat of the snail darter.

1981: Black-footed ferrets are rediscovered near Meeteetse, Wyoming, ending fear that the species was extinct.

1982: Endangered Species Act Amendments of 1982 allow, by permit, the taking of listed wildlife incidental to otherwise lawful activities, provided that the permit holder implements a Habitat Conservation Plan (HCP) for the species. The 1982 amendments also include a prohibition against collecting listed plants on Federal lands.

1983: The nation’s first HCP is approved for the protection of listed species at San Bruno Mountain, California.

1983: Creation of the Interagency Grizzly Bear Committee, made up of bear biologists and representatives of the U.S. Forest Service, National Park Service, U.S. Fish and Wildlife Service, Bureau of Land Management, U.S. Geological Survey, Idaho, Montana, Washington, and Wyoming.

1985: The last nine remaining wild California condors are brought into captivity to prevent the species’ extinction and to begin captive-breeding programs at the San Diego and Los Angeles zoos.

1987: The American alligator is delisted due to recovery.

1987: All 19 remaining black-footed ferrets are taken into captivity and captive breeding is initiated.

1987: The red wolf is reintroduced into the wild at Alligator River National Wildlife Refuge in eastern North Carolina.

1989: Ivory imports are banned in the United States to help reduce poaching of African elephants.

1990: The northern spotted owl is listed as threatened, one of the factors leading to development of the Northwest Forest Plan a few years later.

1991: Captive-propagated black-footed ferrets are reintroduced into Wyoming several years after the last wild population was captured to prevent extinction from disease outbreaks.

1991: California condors are reintroduced into the wild in southern California.

1992: The George H.W. Bush administration imposes a moratorium on new regulations, including ESA listings, leading to the first major listing deadline lawsuit and settlement.

1994: Eastern North Pacific population of gray whales is delisted due to recovery.

1994: The Arctic peregrine falcon is delisted due to recovery.

1994: The U.S. Fish and Wildlife Service first offers “No Surprises” guarantees for Habitat Conservation Plans.

1995: Gray wolves are reintroduced to Yellowstone National Park and central Idaho.

1995: Pinehurst Resort, North Carolina, signs the first Safe Harbor Agreement in the nation; it benefits the endangered red-cockaded woodpecker.

1995: The Carlsbad Highlands Conservation Bank, the first official agreement of its kind for a listed species, was approved for use in association with the San Diego Multiple Species Conservation Plan.

1995: U.S. Supreme Court, in its “Sweet Home” decision, upholds the FWS regulation that defines “harm” to include destroying or modifying habitat for an endangered or threatened species if the action results in the taking of the species.

1996: The California condor is reintroduced into northern Arizona.

1999: The American peregrine falcon is delisted due to recovery.

1999: The U.S. Fish and Wildlife Service formalized both Safe Harbor Agreements and Candidate Conservation Agreements with Assurances.

2000: Oregon Department of Fish and Wildlife develops the nation’s first Candidate Conservation Agreement with Assurances; it benefits the Columbian sharp-tailed grouse.

2001: Aleutian Canada goose is delisted due to recovery.

2001: The Northern Rocky Mountain Distinct Population Segment of gray wolves reaches its recovery goals, but remains listed due to litigation.

2003: Robbins’ cinquefoil, a New England plant, is delisted due to recovery.

2003: The U.S. Fish and Wildlife Service adopts the Policy for Evaluation of Conservation Efforts When Making Listing Decisions, allowing consideration when listing species of conservation efforts that are planned but not yet implemented.

2004: California condors reproduce in the wild for the first time in 17 years.

2007: The bald eagle is delisted following recovery. (The southwestern U.S. population is later listed as threatened.)

2007: The Greater Yellowstone Ecosystem Distinct Population Segment of grizzly bear reaches its recovery goals, but remains listed due to litigation.

2008: The FWS, Bureau of Land Management, and Center of Excellence for Hazardous Materials Management agree to the first joint Candidate Conservation Agreement/Candidate Conservation Agreement with Assurances; it benefits the lesser prairie chicken and the sand dune lizard.

2008: The polar bear is listed as threatened due to habitat loss in the Arctic.

2010: The U.S. Fish and Wildlife Service enters into the ESA Section 4 multidistrict litigation, ultimately agreeing to make listing or critical habitat determinations for 1,030 species, subspecies, and populations by 2017.

2010: The Natural Resources Conservation Service launches the Lesser Prairie Chicken Initiative and the Sage Grouse Initiative.

2011: The Northern Rocky Mountain Distinct Population Segment of gray wolves is delisted by Congressional action, except in Wyoming.

2014: The monarch butterfly is first petitioned for listing under the Endangered Species Act, followed by a second petition in 2020.

2014: The lesser prairie chicken is listed as a threatened species, only to have the listing overturned by a court in 2015.

2015: The greater sage-grouse is determined not to warrant listing. This is due to the largest collaborative conservation effort in American history, an investment that would eventually top $1.5 billion. Federal, state, and private organizations were all involved in myriad conservation programs, with over half of the species’ range secured by Bureau of Land Management Resource Management Plan amendments. These amendments would themselves be reconsidered and changed repeatedly, by both the Trump and Biden administrations.

2016: The Louisiana black bear is delisted.

2017: The gray wolf is delisted in Wyoming.

2017: The rusty-patched bumblebee is listed as an endangered, the first bee in the 48 contiguous states to be listed.

2019: A paper published in the journal Science announces that North America has lost 3 billion birds since 1970, sparking growing awareness of the worldwide biodiversity crisis, and its impact on birds, insects, forests, and other components of Earth’s biosphere.