The Endangered Species Act.
The Act was originated in 1973, and is one of many US environmental laws passed in the 1970's. The law protects species from extinction. The United States Fish and Wildlife Service and the National Oceanic and Atmospheric Administration help to administer the act.
It was amended in 1978 to add economic considerations and again in 1982 which prevented economic considerations.
To be considered for listing, the species must meet one of five criteria (section 4(a)(1)):
1. There is the present or threatened destruction, modification, or curtailment of its habitat or range.
2. An over utilization for commercial, recreational, scientific, or educational purposes.
3. The species is declining due to disease or predation.
4. There is an inadequacy of existing regulatory mechanisms.
5. There are other natural or manmade factors affecting its continued existence.