The Mission of the DHS is to protect the United States from threats, including: terrorism, national security concerns, managing borders, and administering immigration laws.

A-Z Index of Federal Government Agencies

The IRS is the nation's tax collection agency.

• The Internal Revenue Service 

The largest library in the world, the LOC's mission is to provide "[...]Congress, the federal government and the American people with a rich, diverse and enduring source of knowledge to inform, inspire and engage them and support their intellectual and creative endeavors."

"The mission of GSA is to deliver the best value in real estate, acquisition, and technology services to government and the American people."

• U.S. General Services Administration 

The Treasury Department is the executive agency responsible for promoting economic prosperity and ensuring the financial security of the United States.

The USDA provides "leadership on food, agriculture, natural resources, rural development, nutrition, and related issues based on public policy, the best available science, and effective management.'

• United States Department of Agriculture