The AbilityOne Commission creates job opportunities for people who are blind or have other significant disabilities in the manufacture and delivery of products and services to the Federal Government.

The Access Board is an independent federal agency devoted to accessibility for people with disabilities. The Board develops and maintains design criteria for the built environment, transit vehicles, telecommunications equipment, and for electronic and information technology.

The Administration for Children and Families funds state, territory, local, and tribal organizations to provide family assistance (welfare), child support, child care, Head Start, child welfare, and other programs relating to children and families.

The Administration for Community Living supports the needs of the aging and disability populations, and improves access health care and long-term services.

The Administration for Native Americans promotes self-sufficiency and cultural preservation for Native Americans by providing social and economic development opportunities through financial assistance, training, and technical assistance.

The Administrative Conference of the United States is an independent federal agency dedicated to improving federal agency administrative processes and procedures.

The Administrative Office of the United States Courts handles the nonjudicial, administrative business of the United States Courts such as maintaining statistics and managing Court budgets.

The Advisory Council on Historic Preservation encourages the preservation of historic properties across the nation.

The U.S. Africa Command strengthens the defense capabilities of African nations.

The African Development Foundation provides grants to community groups and small enterprises that benefit under-served and marginalized groups in Africa.

The U.S. Agency for Global Media, formerly known as the Broadcasting Board of Governors, broadcasts news and information about the United States and the world to audiences abroad.

The Agency for Healthcare Research and Quality supports research to improve the quality, safety, efficiency, and effectiveness of health care for all Americans.

The U.S. Agency for International Development (USAID) is the principal U.S. agency to extend assistance to countries recovering from disaster, trying to escape poverty, and engaging in democratic reforms.

The Agency for Toxic Substances and Disease Registry responds to, and protects people from harmful chemical exposures.

The Agricultural Marketing Service supports the fair marketing of U.S. agricultural products.

The Agricultural Research Service works to find solutions to agricultural problems.

The Department of Agriculture provides leadership on food, agriculture, natural resources, and related issues.

The National Agricultural Library is the main source of information and research on agriculture.

The Air Force defends the United States in the air and space.

The Air Force Reserve Command performs missions and supports Air Force operations.

The Alcohol and Tobacco Tax and Trade Bureau collects taxes and enforces regulations on alcohol, tobacco, firearms, and ammunition.

The Bureau of Alcohol, Tobacco, Firearms and Explosives enforces federal criminal laws regulating the firearms and explosives industries.

The Middle East Broadcasting Network operates Alhurra TV and Radio Sawa. Alhurra TV and Radio Sawa provide news to the people of the Middle East about the region, the world, and the United States.

The American Battle Monuments Commission manages 24 military cemeteries abroad, and 25 memorials, monuments, and markers. Nearly all the cemeteries and memorials honor those who served in World War I or World War II.

Formerly known as the Corporation for National and Community Service, AmeriCorps, and AmeriCorps Seniors engage volunteers in serving directly with nonprofit organizations to tackle the nation's most pressing challenges.

AmeriCorps Seniors is a network of volunteer programs for Americans 55 years and older. Volunteers work in their community doing academic tutoring and mentoring, elderly care, disaster relief, and more.

Amtrak, the National Railroad Passenger Corporation, provides intercity rail passenger service.

The Animal and Plant Health Inspection Service protects and promotes U.S. agricultural health, regulates genetically engineered organisms, administers the Animal Welfare Act, and manages wildlife damage.

The Antitrust Division promotes economic competition through enforcing and providing guidance on antitrust laws and principles.

The Appalachian Regional Commission works for sustainable community and economic development in Appalachia.

The Architect of the Capitol manages and maintains the U.S. Capitol, the Capitol Visitor Center, the Senate Office Buildings, the House Office Buildings, the Supreme Court Building, the Library of Congress, the U.S. Botanic Garden, and the Capitol Grounds

The National Archives and Records Administration preserves U.S. government records, manages the Presidential Libraries system, and publishes laws, regulations, Presidential, and other public documents.

The U.S. Arctic Research Commission develops and recommends a national Arctic research policy.

The Gulfport and Washington campuses of the Armed Forces Retirement Home are retirement centers for veterans of the U.S. military.

The under secretary of state for Arms Control and International Security serves as senior adviser to the president and the secretary of state for arms control, nonproliferation, and disarmament.

The U.S. Army organizes, trains, and equips active duty and Reserve forces to preserve the peace, security, and defense of the United States.

The Army Corps of Engineers provides public engineering services in peace and war to strengthen national security, energize the economy, and reduce risks from disasters.

The National Institute of Arthritis and Musculoskeletal and Skin Diseases supports research into the causes, treatment, and prevention of arthritis, musculoskeletal, and skin diseases.