What Is the Louisiana Purchase?

Pierre LeMoyne, Sieur d'Iberville, established the French colony of Louisiana in 1699. In 1714, Natchitoches became the first permanent French settlement in the huge Louisiana Territory. New Orleans, the colonial capital was founded in 1718.

In 1754, the "French and Indian War" began. France, aided by Spain, vainly battled the British in North America and in Europe and Asia where the conflict was known as the Seven Years' War. A victorious Great Britain imposed the Peace of Paris in France and Spain in 1763. The French compensated the Spaniards for the loss of Florida to the British by presenting them with Louisiana.

After overcoming the initial hostility of the colony's French inhabitants, Spanish authorities established a strict and efficient administration to govern Louisiana. For Spain, as with France, the colony was not yet especially profitable and liabilities outnumbered assets.

Spanish forces in Louisiana assisted the new United States in the War for American Independence. The Treaty of Paris in 1783 confirmed the "nationhood" of the American republic and also returned Florida to Spain. American settlers pushed into the Ohio Valley and into Tennessee and Kentucky. Their recent allies, the Spaniards, viewed this advancing frontier with alarm.

The Americans, who were busily planting crops and building towns, found that it was increasingly difficult to transport goods and produce eastward over the Appalachian and Allegheny Mountains to the cities and markets of the Atlantic coast. The Ohio and Mississippi Rivers were natural highways which the frontiersmen realized could be easily used to ship crops, livestock, and other items to buyers. New Orleans, an expanding and now prosperous port city, was the beacon which attracted the Americans of the early West.

Fearful of a growing American presence, Spanish officials took action to limit the use of the Mississippi, and of New Orleans, by the settlers. On occasion, war loomed between Spain and the United States. In 1795, however, the Pinckney Treaty reduced tension by granting "permanent" trade privileges to the Americans.

France, meanwhile, had suffered through the horrors of revolution and sought stability and glory in the person of Napoleon Bonaparte. In 1800, the French forced Spain to yield Louisiana in the secret Treaty of San Ildefonso. Rumors of the treaty reached the United States and the threat of an aggressive Bonaparte closing New Orleans to American trade seemed real.

France, however, had no intention of re-establishing its North American empire. A slave revolt on Santo Domingo and the omnipresent danger of yellow fever convinced Bonaparte that possessions in the western hemisphere were not worth the blood and treasure necessary to hold them. Moreover, the French needed money to maintain and expand their forces in Europe. Locked in conflict with several nations, Napoleon Bonaparte's first concern was the defense of France itself through bold offensive action.

President Thomas Jefferson of the United States, in a bold move of his own, instructed special envoy James Monroe and American Minister to France Robert Livingston to discuss with the French the possible purchase of the port of New Orleans. Monroe and Livingston were astonished when Francois Barbé-Marbois, at Bonaparte's order, offered the entire Louisiana Territory to the United States. Although they lacked Constitutional authority, the American representatives agreed to buy all of the massive territory which extended from Canada to the Gulf of Mexico and from the Mississippi River to the Rocky Mountains for a total of nearly fifteen million dollars -- an extraordinary bargain at four cents an acre. A Treaty of Cession was signed on April 30, 1803 in Paris.

President Jefferson, a believer in strict adherence to the Constitution, was concerned about the legality of purchasing Louisiana before the agreement could be ratified by the Senate but he supported the decision made by Monroe and Livingston. Debate over the purchase and over the addition of an "alien population" to the United States was intense with the New England states eager to condemn the acquisition of Louisiana and the frontier states of the South and West just as eager to defend it. On October 25, the Treaty of Cession was approved by the Senate and, shortly thereafter, the transfer of power took place in New Orleans. By the single act of purchasing the Louisiana Territory, the United States of America doubled its size and greatly accelerated its march toward the Pacific coast. The beckoning West awaited a new generation of pioneers who would turn the dream of "manifest destiny" into the reality.

In 1804, President Thomas Jefferson instructed Meriwether Lewis and William Clark to explore the newly-acquired Louisiana Territory. The two military men led an expedition of forty-five soldiers, woodsmen, and hunters into the unknown wilderness of plains and mountains. Departing St. Louis, they traveled up the Missouri River and, in 1805, crossed the Rockies to enter the Oregon country. In 1806, Lewis and Clark returned in triumph to St. Louis. The expedition succeeded in mapping much of the northern part of the Louisiana Territory and in giving the United States a valid claim to the Pacific Northwest. Hundreds, then thousands, of settlers followed them. Eventually, fifteen states would be created from the vast land known as Louisiana.

The Louisiana Purchase and the Lewis and Clark Expedition guaranteed the continuing westward march of the United States. By the 1840's, most Americans fervently believed that it was the destiny of the nation to extend from sea to sea. The Mexican War, the Oregon Treaty, and the Gadsden Purchase completed what Robert Livingston and James Monroe had begun and the "Manifest Destiny" of the United States of America became a reality.