Well, I meant the LOCATION, not the name, but that's more of an oversight on my part.
Also, while I agree that I probably could expand further inland, I don't see why not expanding is so much of a problem. Nuova Venezia's location is ideal to control ANY trade coming in from the interior, so there's no need to push further into territory that would be hard to control (easier to travel down stream than upstream), and the coast has its advantages as well, I imagine it's still rather fertile, and there is of course the fishing, and later on the oil.
In other words, it's a perfectly viable country controlling a very strategic location which doesn't make it necessary to make an expensive push in-land.
EDIT: I should also point out that there wouldn't be significant problems for any country located along the Mississippi river; even though I control their access to the sea, they still have (theoretical) access.