The Federal Power Act of 1920 was the first major piece of energy legislation in the United States. It established the Federal Power Commission, which was responsible for regulating the interstate transmission of electricity.

The Public Utility Holding Company Act of 1935 was passed in response to the concentration of power in the hands of a few large utility holding companies. The act required these companies to divest themselves of their subsidiaries and to limit their activities to a single state.

The Natural Gas Act of 1938 was the first federal law to regulate the interstate transportation of natural gas. It established the Federal Power Commission as the regulatory agency for the natural gas industry.

The Energy Policy Act of 1992 was a comprehensive energy law that had a number of goals, including reducing the nation's dependence on foreign oil, promoting the development of renewable energy sources, and improving the efficiency of energy use.

Nuclear power is not a major source of energy in the United States, accounting for only about 10% of the nation's electricity generation.

Hydropower is the most common type of renewable energy in the United States, accounting for about 6% of the nation's electricity generation.

Transportation is the largest source of greenhouse gas emissions in the United States, accounting for about 29% of the nation's total emissions.

The Clean Power Plan is a federal regulation that was issued by the Environmental Protection Agency in 2015. The plan requires states to reduce carbon dioxide emissions from their power plants by 32% below 2005 levels by 2030.

The Paris Agreement is an international agreement that was adopted by 196 countries at the 21st Conference of the Parties to the United Nations Framework Convention on Climate Change in 2015. The agreement aims to limit global warming to well below 2 degrees Celsius, preferably to 1.5 degrees Celsius, compared to pre-industrial levels.

The future of energy law is likely to be shaped by a number of factors, including the increasing use of renewable energy sources, the development of new energy technologies, and the globalization of the energy market.