Answer:
During his presidency, Thomas Jefferson made the Louisiana Purchase.
Step-by-step explanation:
The Louisiana Purchase was a commercial transaction whereby Napoleon Bonaparte, then First Consul of France, sold in 1803 529,911,680 acres of French possessions in North America to the United States at a price of about 3 cents per acre; a total price of 15 million dollars or 80 million French francs. With interest, Louisiana's territory costed $ 23,213,568.
The purchase was important for the presidency of Thomas Jefferson. Although there were doubts about the constitutionality of the acquisition of the territory, he decided to buy Louisiana because he did not like the idea that France and Spain had the power to block the access of American merchants to the port of New Orleans. For the United States, this negotiation opened the access to the Pacific Ocean and dramatically increased its territory.