The Spy Museum and the NRA Museum — free.
I’ve never been to the Spy museum but my grandkids loved it.
I’m not a huge gun fan, but I loved the NRA museum. My husband and I stayed all day. The exhibits are interesting and beautifully done. I believe it is in Arlington, just outside DC.
Also, don’t miss Mt. Vernon. I understand that it has been refurbished since I was there about 10 years ago. Any of your kids who have been subjected to the public school brainwashing meme that “George Washington was ill-educated and couldn’t spell...” will be blown away by seeing all that he and Martha had to manage to keep that farm running & profitable.
If you are interested in period furniture, you should see the DAR Headquarters/Museum. It’s free too, as I remember. There are multiple rooms that have been donated by State chapters and furnished in historic style that replicates some important point in their history.
Ok, have the Spy museum on the map we have. Oldest son who wants to go into law enforcement wants to see that ... (don't know if we'll have time.) Where's the NRA museum? Don't see that on our map. Our oldest son (17) would love to see that.
Oops, you told me in your post where the NRA museum is, TYVM!