Great use of a historic building in a good location to host a mix of permanent and temporary exhibits.
Not the expected static signs about life in a 19th century fort; all the exhibits were engaging and interesting with many well-presented artifacts. No endless cases of stuff or book-length signs here.
The price is a tad high, but check their website: there are several ways to at least knock it down a couple bucks including (as of my visit) showing your metro fare.
There were even enough activities to keep my toddler occupied while we took it in, which is more that I can reasonably ask of any museum.