I'd say this is one of those things you visit for a quickie. Maybe 30-45 minutes. Go in the main house and read everything and then walk around a bit. It's fine if you want to walk on a nice day around, but there's not a wealth of things to see that would occupy hours of your life. I'd give it more time if you are a serious Civil War buff and go on the tour. I stayed with it for about 20 minutes and got a bit bored.
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