Hi Basil,

It depends on what type of job you want in the end - if you'd like to be an independent contractor then you could look at placement firms, if you want to be an employee you can look at consulting firms or recruiters.  I only know a little bit about the US market, but if DC is like any other government town then it's likely that there are many opportunities within contracting firms or consulting firms.

Here's a few suggestions:

• Indeed (http://www.indeed.com/) is a great meta-search engine that scans most of the popular job boards in the country.  You can scan BA jobs by contract or permanent basis and by salary/wage range.  This can give you a quick survey of what the job market looks like in any municipality in the US or Canada.
• Start searching for BAs who are working in or near DC via LinkedIn, Facebook, Twitter, etc.  Look for common contacts who can make an introduction for you.  Ask them for some more info on the local job market and see what they think of the prospects.  Try and give them something of value in return; either a big thank you, coffee or possibly some general BA tips if they're less experienced than you.
• Contact the local IIBA chapter (http://www.iibadc.org).  If you're an IIBA member local chapters are a great way to meet other BAs, find out about the BA scene in an area, and find out about opportunities that companies choose to post with the IIBA first.  Go to the first meeting you can when you get to DC and start networking.

Best of luck to you!