In the late 20th century, the federal government responded to the growing pollution problem across the country and protestations from American citizens with two pieces of legislation aimed at keeping the country’s air, land, and water clean. The United States Environmental Protection Agency is responsible for setting limits for pollution and enforcing these landmark rules.     

In 1990, Congress passed the Clear Air Act Amendments aimed at curbing three major threats to the nation's environment and to the health of millions of Americans: acid rain, urban air pollution, and toxic air emissions. The Clean Air and Water acts have faced much scrutiny over the past 50 years, particularly from business and industry who feel that the government is restricting their abilities to operate, as well as from state governments who push back against the federal government’s right to regulate water within their state borders.