Dinner at the Big Texan Steak Ranch in Amarillo. Consider staying at Palo Duro Canyon State Park while in Amarillo. Its just a few miles south of town and its known as the Grand Canyon of Texas.
While in the Dallas area go to the Ft. Worth Stock Yards. If anyone is interested in historical military aircraft then a stop at the Commemorative Air Force museum is a must. Located at the Dallas Executive Airport. NASA tours in Houston.
Pensacola has the National Naval Aviation Museum too. Lafayette has some old plantation houses you can tour. You may have to do a bit of a drive to get to them.