The Louisiana Purchase of 1803 brought into the United States about 828,000 square miles of territory from France, thereby doubling the size of the young republic. What was known at the time as the 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.

France in the New World

Beginning in the 17th century, France explored the Mississippi River valley and established scattered settlements in the region.

By the middle of the 18th century, France controlled more of the present-day United States than any other European power: from New Orleans northeast to the Great Lakes and northwest to modern-day Montana.

In 1762, during the French and Indian War, France ceded French Louisiana west of the Mississippi River to Spain and in 1763 transferred nearly all of its remaining North American holdings to Great Britain. Spain, no longer a dominant European power, did little to develop Louisiana during the next three decades.

Louisiana Territory Changes Hands

In 1796, Spain allied itself with France, leading Britain to use its powerful navy to cut off Spain from America. And in 1801, Spain signed a secret treaty with France to return the Louisiana Territory to France.

Reports of the retrocession caused considerable unease 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, 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, President Thomas Jefferson 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 Finance Minister Barbé-Marbois for the purchase of New Orleans.

Louisiana Purchase Negotiations

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 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’s 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 – combined with French economic difficulties – may have prompted Napoleon to offer Louisiana for sale to the United States.

Negotiations moved swiftly, and at the end of April the U.S. envoys agreed to pay $11,250,000 and assume claims of American citizens against France in the amount of $3,750,000. In exchange, the United States acquired the vast domain of Louisiana Territory, some 828,000 square miles of land.

The treaty was dated April 30 and signed on May 2. In October, the U.S. Senate ratified the purchase, and in December 1803 France transferred authority over the region to the United States.

Legacy of the Louisiana Purchase

The acquisition of the Louisiana Territory for the bargain price of less than three cents an acre was among Jefferson’s most notable achievements as president. American expansion westward into the new lands began immediately, and in 1804 a territorial government was established.

Jefferson soon commissioned the Lewis and Clark Expedition, led by Meriwether Lewis and William Clark, to explore the territory acquired in the Louisiana Purchase.

On April 30, 1812, exactly nine years after the Louisiana Purchase agreement was made, the first state to be carved from the territory – Louisiana – was admitted into the Union as the 18th U.S. state.

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