The oldest federal agency in the United States is the United States Postal Service (USPS), which traces its origins back to 1775 when the Second Continental Congress established the position of Postmaster General. This agency has played a crucial role in the development of communication in the country. Although it was officially established as an independent agency in 1971, its roots in American history make it the oldest federal entity still in operation today.
If you take into consideration the fact that the US Coast Guard is charged with enforcing the nations laws, then it would be THAT agency which began its life as the US Revenue Cutter Service.
The oldest federal agency in the U.S.A is the U.S. Marshals Office Provided by Jamason Wells W.T.I. Florida
usps
The Environmental Protection Agency.
That would be FEMA which stands for the Federal Emergency Management Agency.
Where? In the US its the IRS.
employee (US Federal worker and/or manager)
In the US, the federal agency responsible for enforcing import and export laws is the U.S. Customs and Border Protection (CBP).
http://www.answers.com/topic/us-department-of-defense
FDA
Yes, it is.
yes it is... it stands for the Federal Bureau of Investigation