I've long thought that the 5 areas we see in the game are only part of the states, not the full state. They have very unusual shapes for states. This was all but confirmed in the trivia section for Ambarino, which said that there must be more civilization in the state for it to have its government(and thus exist as a state), civilization we don't see, hence, not in the game but still exists. So I think that the states in the game extend beyond what we see on the map, except maybe Lemoyne