Me I would go to Nashville, TN (via Skyline Drive if that interests you) spend a day in Nashville and see something at the Ryman auditorium. From there the NATCHEZ TRACE ( Free campgrounds with no services)to Jackson, MS ). Stop off in Tupelo if Elvis Presley home town interests you.
From Jackson take I55 south to New Orleans. Take all the street cars through town. There is a CG right in town but it is $$$
Then to Lafayette, La and stop at Randol's restaurant for great food and Cajun music and dancing. Ask the manager where to park overnight if you do not need services.
Then drop down through Abbeville to Louisiana SR 82 which runs across Louisiana on the gulf. Take the really small ferry in Cameron, LA watch for the Dolphins in the water.
Just past Cameron is Holly Beach where you can stay on the beach for a night or 2 great sea shelling. At Port Aurthur Texas get on I 10 through Houston (THAT IS A BIG CITY), Just after Houston get on 290 to Austin, TX. See a rodeo if one is in town or watch the thousands of bats come out from under the bridge. Nice Texas park Campground just outside Austin. _____ Falls State Park (Name escapes me) See Texas band and learn to two step.
From there continue on 290to Fredericksburg, TX for some great German food. Your DW and daughter will love the shopping. Lady Bird park has an adequate CG. Continue on 290 to I10 spend a night at Fort Stockton, TX.
Then I am afraid it is basically I10 to Tucson but EL Paso is interesting and if you have passports a DAY trip via bus to Ciudad Juarez or walk across.
Through New Mexico and Arizona there are still some kitsch type roadside attractions that are fast disappearing from the American scene and a few of these must be seen before they are gone. Just like the OLD MOTHER ROAD places a gone.
BTW WHAT ARE YOU driving on this trip?
