In the United States the Endangered Species Preservation Act of 1966 (Public Law 89-669) was the predecessor to the Endangered Species Act.Passed by Congress, this act permitted the listing of native U.S animal species as endangered and for limited protections upon those animals.
This Act caused the Secretary of the Interior to initiate and carry out program efforts to conserve, restore, and in some cases propagate certain species of indigenous fish and wildlife he determined to be in danger of extinction. The Act also consolidated and even expanded authority for the Secretary of the Interior to manage and administer the National Wildlife Refuge System. However, with time, researchers noticed that the animals on the endangered species list were not getting enough protection, thus further threatening their extinction. The endangered species program was expanded by the Endangered Species Act of 1969.
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