The fact that mankind has desecrated much of the natural world is recognized. The rate of plant and animal extinction has increased in North America from an estimated 3 species per century 3,000 years ago to an average of 143 per century since 1620. Endangered species protection began in the Fish and Wildlife Service in 1938 with the purpose of the Aransas National Wildlife Refuge for the whooping crane. A committee on rare and endangered species was formed in 1962 by the director of the Fish and Wildlife Service and a tentative list was published in 1964. The Endangered Species Acts of 1966, 1969, and 1973, together with subsequent amendments, provide the legislative authority for the present program. The intent of Congress, through this legislative authority, is to avoid irreversible or irretrievable commitments of resources by identifying problems of environmental impact projects early in the planning stage. Examples in the step-by-step development of the legislation and its operation were reviewed.
Spinks, John L.
Great Basin Naturalist Memoirs: Vol. 3
, Article 4.
Available at: http://scholarsarchive.byu.edu/gbnm/vol3/iss1/4