What departments are there in the U.S. government?

The main departments of the U.S. government are: FBI, CIA, National Security Agency, Department of Defense, Department of Agriculture, Department of the Interior, Department of Labor, Department of State, Department of Transportation, Department of Justice, Department of Education, Health Department of Energy, Department of Veterans, Department of Housing and Urban Development, Department of Homeland Security, Narcotics Control Bureau, U.S. Immigration and Customs Enforcement, Internal Revenue Service/IRS, Bureau of Alcohol, Tobacco, Firearms and Explosives, U.S. Navy Criminal Bureau of Investigation, U.S. Naval Judge Advocate General, U.S. Government Counsel, U.S. Naturalization and Immigration Service, U.S. Postal Service, National Securities and Exchange Commission, Federal Communications Commission, Federal Trade Commission, FAA, National Transportation Safety Board Committee, General Services Administration, Defense Intelligence Agency, National Reconnaissance Office, National Geospatial-Intelligence Agency, Environmental Protection Agency, Federal Election Commission, NASA, National Science Foundation, United States National Railroad Corporation, U.S. Social Security Administration, U.S. Oceanic and Atmospheric Administration, U.S. Geological Survey, Federal Emergency Management Agency, U.S. Customs and Border Protection, Centers for Disease Control and Defense, National Food and Drug Administration, National Institute of Medicine, U.S. Department of Defense Advanced Research Projects Agency.