I have yet to meet anyone outside of the state that says "Man, tell me about Shreveport " or Monroe or (insert town). Think about it, the churches, the bayous, LSU, the Saints, the plantations, the sugar cane, the crawfish, the swamp, the gulf. Literally every single thing the state of LA is known for is South of I-10. You don't have to like it but you cannot dispute it.
Look, im not saying those northerners aren't from "Louisiana" just making the point that the state is known for all things south of the interstate