re: Washington DC trip with kids (10 & 12yo)

I have a child who lives in Arlington. When we visit we go to the George Washington University Inn. LINK / It's on the orange line which is very convenient.

I would definitely take them to the Spy Museum though I think they are getting ready to move, so you may want to check on that. It's full of fun stuff, and though it's not cheap it has great stuff, like James Bond cars, etc.

Also if they really are in to history Ford's Theatre is great, but you need to check on scheduled tours. I don't know if you can book in advance, but if not get there early, or you'll have to go back later in the day for your tour.

Also, check out the night that the Marine Corp Band is playing at the Iwo Jima Monument at Arlington Cemetery. It's quite impressive, and there are all sorts of dignitaries there in their uniforms. Nice display on precision too.

I'll check with my kid to see if there is anything else that might recommend.