Whataburger is a major chain located mostly the Southern U.S. states. Their food is amazing!
They have a very thorough allergy menu and are so friendly and helpful if you have questions. Despite my tree nut allergy I got to try so many new things like malts which I have never had before.
Just like any other tourist attraction, if your vacationing somewhere that has Whataburger locations, you must add to your list!