For 35 years, ever since Richard Nixon signed it into law in December 1973, the Endangered Species Act has served as a biological half-way house, a kind of protective legal custody for life-forms at risk of disappearing. It would be more accurate, in a way, to call it the Endangered Species and Habitat Act, since the purpose of the law is to protect species by identifying and then protecting their critical habitat—old-growth forest for the northern spotted owl, the Little Tennessee River for the snail darter. The act has been controversial ever since it was signed, not because it tries to save plants and wildlife but because it tries to save the habitat they need to survive. Usually—and here is where the trouble arises—this means preventing humans from altering those ecosystems in any way.
What passed in 1973 was a lean, tough act. It called upon every department and agency in the federal government to work explicitly toward protecting endangered and threatened species. It required the federal government to cooperate with state governments in doing so, and it pledged the United States to live up to several international treaties whose purpose is to conserve species facing extinction. It was, in a sense, a bill of rights for the rest of creation.
There was a sense of urgency in the act—an urgency it shared with the Clean Air and Clean Water Acts of 1970 and 1972. What inspired them all was a groundswell of environmental awareness rising from many sources—including Rachel Carson’s Silent Spring, published in 1962—and the sudden, painful realization that many species, whales and whooping cranes alike, were collapsing in numbers.