Hey Guys,
If the Americans (for some reason) were unable to buy/annex/conquer/own Louisiana and were unable to have mass amounts of settlers there, would the American people have settled elsewhere in large waves. Without being able to 'Go West' where could they have gone? Would they have begun to settle Florida in mass waves, and from there the Caribbean? Maybe even the East coast of New Spain (such as Yucatán perhaps).
Or without the huge land of Louisiana would the Americans have just dealt with their own internal 'problems' (i.e. The Natives).