bobsallyh wrote:
Try Bull Run County Park just off Bull Run Battlefield. Metro station just short up the road. We always used this for sightseeing or ball games in the DC area. Metro is so easy to use.
OP is staying at a motel, not RV. As Metro does not run directly from Bull Run Battlefield, you could alternatively take the
Virginia Railway Express (VRE), a commuter train one can catch in Manassas city. From there, you could transfer to Metro Blue Line at Crystal City (Amazon HQ2). Or continue to L'Enfant Plaza station and walk a few blocks to the National Mall. Or finally at Union Station which is closest to the U.S. Capitol.