Louisiana Purchase: America Doubles in Size for $15 Million

Robert Livingston and James Monroe signed the Louisiana Purchase treaty in Paris on April 30, 1803, acquiring 828,000 square miles of territory from France for $15 million, approximately four cents per acre. The deal doubled the size of the United States overnight, extending its western boundary from the Mississippi River to the Rocky Mountains and encompassing all or part of fifteen future states. Napoleon Bonaparte, who had reacquired the territory from Spain only three years earlier, sold it because his ambitions in the Western Hemisphere had collapsed and he needed cash for his European wars. Napoleon's decision was driven by the catastrophic failure of his attempt to reimpose French control over Saint-Domingue, modern Haiti. An expedition of 20,000 soldiers sent in 1801 to crush the Haitian Revolution was devastated by yellow fever and fierce resistance led by Toussaint Louverture and Jean-Jacques Dessalines. Without Saint-Domingue as a base, Louisiana was strategically useless to France, and Napoleon decided to sell before the British navy could seize it during the next round of European warfare. "I renounce Louisiana," he told his finance minister. "I have already given England a maritime rival who will sooner or later humble her pride." President Thomas Jefferson, who had sent Livingston and Monroe to Paris to buy only New Orleans and the Floridas for up to $10 million, was astonished by the scope of the offer. He also had serious constitutional concerns. The Constitution did not explicitly authorize the president to acquire foreign territory, and Jefferson, a strict constructionist, recognized the contradiction between his political philosophy and the executive action he was taking. He considered proposing a constitutional amendment but ultimately decided the opportunity was too important to risk losing to congressional delay. The Louisiana Purchase transformed the United States from a coastal republic into a continental power. The territory contained the port of New Orleans, the entire Mississippi River drainage, and the agricultural heartland that would feed American expansion for the next century. Lewis and Clark's expedition, launched in 1804 to explore the new acquisition, revealed its staggering scale and diversity. The purchase also deepened the crisis over slavery, since every new territory raised the question of whether it would be free or slave, a question that the Missouri Compromise of 1820 attempted to answer and that the Civil War ultimately decided.