EPA

The U.S. Environmental Protection Agency — created by Nixon in 1970 to set and enforce environmental standards, including the Clean Air Act and Clean Water Act.

Environmental regulatory infrastructure: the EPA's creation institutionalized the principle that pollution is a market externality requiring governmental correction. The Clean Air Act (1970), Clean Water Act (1972), and Superfund (CERCLA, 1980) are its foundational legislative mandates. The EPA represents the high-water mark of American regulatory state expansion — bipartisan at founding (Nixon), subsequently contested. Its regulatory power over greenhouse gases (established by Massachusetts v. EPA, 2007) is the primary U.S. legal mechanism for climate policy.