So if you look at a map of the continental US it's abundantly clear that there's one state that's not like the others, and at 2.14 million km² it really really sticks out, dwarfing even Alaska. So what if the Americans did what they did with Northwest Territory and split it up into many smaller states as various localities attained suitable population densities?
(OOC: and just to clarify I'm thinking this state of Louisiana is the entire Louisiana Purchase, ie not even divided between The District of Louisiana and Orleans Territory)