Where can I find a complete list of all organizations in the Baltimore and Washington DC areas?|124617

By organizations I mean all businesses, nonprofit organizations, and advocacy groups. This is really urgent, so please help me to find a resource that has this information.

You can do searches for non-profits at GuideStar by location (_advanced search_ by state -- includes D.C. -- and/or city, such as Baltimore); however, you_d have to enter suburban cities for Washington, D.C. to be most inclusive of the Metro D.C. area (like Arlington or Alexandria, VA, etc.), if that is your request/need.