For being on the small side, this museum is very well curated and has a lot of information about how "regular" folks were impacted by the Civil War. The dioramas are as lifelike as any mannekins can be. There are many artifacts to look at and read about in depth. I enjoyed the 3-D pictures - I had no idea that photographers of the time expected their work to be seen using a stereoscope! One short little film was especially good when viewed through the disposable glasses.
The "feature" film at 18 minutes gave a very understandable presentation of the flow of the Battle of Gettysburg, interesting enough that even the high school aged kids were quiet and respectful throughout.
I didn't stop to browse the shop, but they certainly have a lot of stuff one can buy, including several shelves of books. Nice staff, ample parking in back or possibly across the street.