The **U.S. Department of Energy (DOE)**, established on October 1, 1977, is a pivotal federal agency responsible for shaping America’s energy policy, advancing scientific research, and managing the nation’s nuclear weapons program[1][2][3]. It was created by the Department of Energy Organization Act under President Jimmy Carter to consolidate fragmented energy programs and address the energy crises of the 1970s by promoting energy conservation, energy independence, and alternative energy development[3][4]. The DOE’s origins trace back to two major traditions merged into one agency: defense-related nuclear programs initiated during World War II’s Manhattan Project, which developed the atomic bomb, and a collection of disparate energy-related federal programs[1][2]. The Manhattan Project was a massive wartime effort involving top scientists and tens of thousands of workers, laying the foundation for DOE’s ongoing nuclear weapons stewardship and national laboratory system[2][3]. After the war, the Atomic Energy Commission managed nuclear energy until the 1974 Energy Reorganization Act split regulatory and development functions, leading to the DOE’s eventual formation[3]. Key achievements of the DOE include managing the U.S. nuclear weapons stockpile, advancing energy research and development through its Office of Science, and overseeing national laboratories that drive innovation in clean energy, physics, and other fields[7]. The DOE also plays a critical role in energy policy, including strategic petroleum reserves, fuel efficiency standards, and environmental regulations[4][5]. Today, the DOE employs about 16,000 permanent staff and oversees approximately 100,000 contractors working at national labs and facilities[4][5]. It remains central to U.S. efforts to transition to sustainable energy, enhance energy security, and maintain technological leadership in nuclear and renewable energy domains. Notably, the DOE integrates complex energy and defense missions uniquely, balancing national security with advancing cutting-edge energy technologies, making it a key player in both business and technology sectors[1][7].