Sagot :
President Jefferson doubled the size of the United States through the Louisiana Purchase. In this purchase, Jefferson bought the land that is now known as the entire Midwest and parts of the South from France under the rule of Napoleon Bonaparte. World events made it possible because the only reason Napoleon sold the entire area to Jefferson was due to an impending war with Britain after disputes involving the Continental System (a French blockade on British trading) and a revolt in Haiti, with Napoleonic France badly needing the money from the purchase.
France, at that time, had no money and Jefferson knew that, so he took advantage of their desperation for money, bargained with the French and ultimately doubled the size of America for very cheap.