The correct answer is France.
Jefferson bought the Louisiana Purchase from France in 1803. This would be a huge turning point in the United States, as it nearly doubled the size of the US. This purchase resulted in the US gaining 800,00 square miles of territory. Ultimately, the Louisiana territory would become 13 different states as it became settled. This also extended the power of the executive branch, as it was determined that presidents do thave the power to buy land from other countries.
