Final answer:
The National Environmental Policy Act of 1969 is the act that establishes a national environmental policy for the protection and enhancement of the environment, working alongside other environmental laws and regulatory measures enforced by the EPA.
Step-by-step explanation:
The environmental act that establishes a national environmental policy with goals for the protection, maintenance, and enhancement of the environment is the National Environmental Policy Act (NEPA) of 1969. This act provided a framework for environmental decision-making in the United States. NEPA requires federal agencies to assess the environmental effects of their proposed actions before making decisions. It is a foundational environmental law that has influenced national regulations, including the Clean Air Act of 1963, the Clean Water Act of 1972, and the Endangered Species Act of 1973. The creation of the Environmental Protection Agency (EPA) in 1970 marked a significant step in federal environmental governance, allowing for a more coordinated approach to enforcing national environmental policies and ensuring that America's air and water have become cleaner in recent decades.