Based on the excerpt, the statement that can be inferred about the effect the Louisiana Purchase would have on the United States is:
Because of the purchase of the territory, Americans could now legally start settling regions in the West.
The excerpt discusses how the Louisiana Purchase doubled the size of the country and paved the way for westward expansion, indicating that the acquisition of this territory would allow Americans to settle in the West. The other statements regarding presidential power, public debt, or the threat from France are not directly supported by the information provided in the excerpt.