One of the richest and most diverse histories of the Federal Government is the Department of Energy. The Department has been in existence only since 1977. Its roots can be traced back to the Manhattan Project efforts to create the atomic bomb, as well as to various energy-related programs previously dispersed across various Federal agencies. The Energy Department's mission is to secure America's prosperity and security through the development of science-based technology solutions that address America’s energy, nuclear and environmental challenges. Jennifer Granholm is the United States Secretary for Energy. She leads the agency charged with maintaining an effective, safe and secure nuclear deterrent, reducing the risk of nuclear proliferation, supervising the United States energy supply, and carrying out environmental cleanup from the Cold War nuclear missions.