The Homeland Security Act of 2002 references the National Capital Region as defined by Title 10, United States Code, Section 2674 (f)(2) which provides the following definition:

The term "National Capital Region" means the geographic area located within the boundaries of

1. The District of Columbia
2. Montgomery and Prince Georges Counties in the State of Maryland
3. Arlington, Fairfax, Loudoun, and Prince William Counties and the City of Alexandria in the Commonwealth of Virginia
4. All cities and other units of government within the geographic areas of such District, Counties, and City

View the National Capital Region with the following maps:

• National Capital Region Overview*
• National Capital Region View with Municipalities*