Thanks for the response. He has travelled a lot in the States but has never been to that part of the South and really wants to see it; the plantations, history etc; just soaking up the atmosphere really. However I am a bit more practical and want to know that there will be things to do and see rather than just wandering about! I have been scared off New Orleans by a pretty horrific documentary screened in the UK lately so wouldn't feel comfortable taking them there.
To give you an idea of what we like we enjoyed doing a tour of the historic stockyards in Fort Worth and seeing the cow parade last time we were over and visit a lot of castles, stately homes, gardens etc in the UK which often have some limited activities for kids (worksheets, animals to pet, dressing up etc) - something cultural but with handy distractions for kids is what we want essentially!