federal agenices not in Washington, DC?

Answer 1

CDC - Atlanta
Nuke Labs - Desert Southwest
Lots of Bio Labs spread throughout the U.S.
Military bases.
West Virginia has a lot of Agencies.
IRS has a lot of regional offices with a lot of employees.

But most headquarters are in the DC area.

If you want to work for a Federal Agency, there are field offices everywhere - most are staffed with entry level and mid-level officers. But if you want to advance, you will end up in DC.

Answer 2

Probably a federal agency in nearly if not every state in the U.S.