1966
On October15，the Endangered Species Preservation Act（P.L.89-669）is signed into law。在现场预应力混凝土endangered speciesby the Secretary of the Interior（additional protection for endangered species is granted with the enactment of the Endangered Species Conservation Act of 1969 and the Endangered Species Act of 1973）。
1973
The Endangered Species Act（P.L.93-522）is adopted to enhance US action to defend endangered species。Endangered species protection is broadended and strengthened by bringing the United States into conformity with the Convention on International Trade in Endangered Species of Wild Fauna and Flora（CITES）。The convention，a3-week event，concludes in Washington，DC with over80participating countries。
1981
The Endangered Species Act is reauthorized by the US Congress after a vigorous battle with special interest groups who tried unsuccessfully，for the most part，to weaken it。
Find out more aboutendangered species。
