Its where you live. Legal residence only applies to people who might have more than one home. You might live in both equally, but one of them is where all important stuff goes. Since you only have one home, and all your documentation says the Louisianna address, then thats your legal address.

The other thing is if you're a college student living at the dorms. Your legal residence would be your parent's house. The only time a college residence become your legal residence is if you moved fulltime into an apartment, and then had all your official stuff like driver's licence and tax documents changed to the apartment address

Or thats how I was always told.