The United States Department of Energy (DOE) is a Cabinet-level department of the United States government concerned with the United States' policies regarding energy and safety in handling nuclear material. Its responsibilities include the nation's nuclear weapons program, nuclear reactor production for the United States Navy, energy conservation, energy-related research, radioactive waste disposal, and domestic energy production. DOE also sponsors more basic and applied scientific research than any other US federal agency; most of this is funded through its system of United States Department of Energy National Laboratories.

The agency is administered by the United States Secretary of Energy, and its headquarters are located in southwest Washington, D.C., on Independence Avenue in the Forrestal Building, named for James Forrestal, as well as in Germantown, Maryland.

In 1942, during World War II, the United States started the Manhattan Project, a project to develop the atomic bomb, under the eye of the U.S. Army Corps of Engineers. After the war, the Atomic Energy Commission was created to control the future of the project.

The term Department of Energy is used by government departments in a number of countries and may refer to:

The United States of America (commonly abbreviated to the United States, the U.S., the USA, America, and the States) is a federal constitutional republic comprising fifty states and a federal district. The country is situated mostly in central North America, where its forty-eight contiguous states and Washington, D.C., the capital district, lie between the Pacific and Atlantic Oceans, bordered by Canada to the north and Mexico to the south. The state of Alaska is in the northwest of the continent, with Canada to the east and Russia to the west, across the Bering Strait. The state of Hawaii is an archipelago in the mid-Pacific. The country also possesses several territories in the Pacific and Caribbean.

At 3.79 million square miles (9.83 million km²) and with over 312 million people, the United States is the third or fourth largest country by total area, and the third largest by both land area and population. It is one of the world's most ethnically diverse and multicultural nations, the product of large-scale immigration from many countries. The U.S. economy is the world's largest national economy, with an estimated 2011 GDP of $15.1 trillion (22% of nominal global GDP and over 19% of global GDP at purchasing-power parity). Per capita income is the world's sixth-highest.

Arnold Alois Schwarzenegger ( /ˈʃwɔrtsənɛɡər/; German: [ˈaɐnɔlt ˈalɔʏs ˈʃvaɐtsənˌʔɛɡɐ]; born July 30, 1947) is an Austrian and American former professional bodybuilder, actor, businessman, investor, and politician. Schwarzenegger served as the 38th Governor of California from 2003 until 2011.

Schwarzenegger began to weight train at the age of 15 years old. He was awarded the title of Mr. Universe at age 20 and went on to win the Mr. Olympia contest seven times. Schwarzenegger has remained a prominent presence in the sport of bodybuilding and he has written several books and numerous articles on the sport. Schwarzenegger gained worldwide fame as a Hollywood action film icon. He was nicknamed the "Austrian Oak" and the "Styrian Oak" in his bodybuilding days, "Arnie" during his acting career and more recently the "Governator" (from "Governor" and "Terminator").

As a Republican, he was first elected on October 7, 2003, in a special recall election to replace then-Governor Gray Davis. Schwarzenegger was sworn in on November 17, 2003, to serve the remainder of Davis's term. Schwarzenegger was then re-elected on November 7, 2006, in California's 2006 gubernatorial election, to serve a full term as governor, defeating Democrat Phil Angelides, who was California State Treasurer at the time. Schwarzenegger was sworn in for his second term on January 5, 2007.