Map showing the area covered by the Louisana Purchase.
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With the Louisiana Purchase in 1803, the United States purchased approximately 828,000,000 square miles of territory from France, thereby doubling the size of the young republic. What was known as Louisiana Territory stretched from the Mississippi River in the east to the Rocky Mountains in the west and from the Gulf of Mexico in the south to the Canadian border in the north. Part or all of 15 states were eventually created from the land deal, which is considered one of the most important achievements of Thomas Jefferson’s presidency.


In 1801, Spain signed a secret treaty with France to return Louisiana Territory to France. Reports of the retrocession caused considerable uneasiness in the United States. Since the late 1780s, Americans had been moving westward into the Ohio River and Tennessee River valleys, and these settlers were highly dependent on free access to the Mississippi River and the strategic port of New Orleans. U.S. officials feared that France, resurgent under the leadership of Napoleon Bonaparte (1769-1821), would soon seek to dominate the Mississippi River and access to the Gulf of Mexico. In a letter to U.S. minister to France Robert Livingston (1746-1813), America’s third president, Thomas Jefferson (1743-1826), stated, “The day that France takes possession of New Orleans…we must marry ourselves to the British fleet and nation.”

Livingston was ordered to negotiate with French minister Charles Maurice de Talleyrand (1754-1838) for the purchase of New Orleans

France was slow in taking control of Louisiana, but in 1802 Spanish authorities, apparently acting under French orders, revoked a U.S.-Spanish treaty that granted Americans the right to store goods in New Orleans. In response, Jefferson sent future U.S. president James Monroe (1758-1831) to Paris to aid Livingston in the New Orleans purchase talks. In mid-April 1803, shortly before Monroe’s arrival, the French asked a surprised Livingston if the United States was interested in purchasing all of Louisiana Territory. It is believed that the failure of France to put down a slave revolution in Haiti, the impending war with Great Britain and probable British naval blockade of France, and financial difficulties may all have prompted Napoleon to offer Louisiana for sale to the United States.

