The only caveate I would add from our own experience is that I don't know how to do a "day trip" to DC. There sure is a lot of goodies to see there. We stayed at Greenbelt in the trailer and took the Metro in town for four days and still didn't cover nearly all of it. The kids loved figuring out the Metro system. Our last night there we ended up staying past dark to see the mall at night and it was clear there is a different "clientelle" who rides the Metro on a Sat. night. I was NOT comfortatble with some of the activity we witnessed. Was glad to get back to the trailer that night.
"It`s not important that you know all the answers, it`s only important to know where to get all the answers" Arone Kleamyck
"...An unarmed man can only flee from evil, and evil is not overcome by fleeing from it." Col. Jeff Cooper
Sunset Creek 298 BH