The Louisiana Purchase: The Origins of American Imperialism

Location of Louisiana Purchase

With the Louisiana Purchase, Thomas Jefferson initiated imperialistic policies in expanding American ideals across this continent and eventually throughout the world.

Did the United States become an imperial power following the overwhelming defeat of the Spanish during the Spanish-American War? Many have argued that the conflict was indeed fought to expand American economic and political influence outside her own borders. However, this was not the first occurrence of American imperial expansion. When Thomas Jefferson purchased the vast Louisiana territories from France he did so with the explicit imperialistic goals of expanding American economic and political influence beyond her own borders.

Louisiana and the French and Indian War

The European powers (Spain, France, and England) immediately recognized the geographic value of the Louisiana region because of its strategic location adjacent to the Mississippi River. Since the Mississippi River provided an outlet into the Gulf of Mexico for goods in the Ohio Valley region, control of the port city, later known as New Orleans, became essential. However, the English victory during the French and Indian War led to France relinquishing Canada and Louisiana.

From the 1760s until the reign of Napoleon, Spain controlled the region with hopes of establishing her own empire in North America. However, the advancing encroachment of the Americans continually concerned the Spaniards. Unable to satisfactorily prevent this westward expansion Spain agreed to an exchange of territories with France to solidify their new alliance against England.

Louisiana and Napoleon

The Federalists feared that if the French regained power in Louisiana, they could limit American access to the perceived limitless natural resources west of the Mississippi River. But the pro-French Jefferson, did not agree with the Federalists objections. Not only was Napoleon preparing to reassume possession of Louisiana, he also wanted to reassert his claim to the island nation of Santo Domingo after black slaves had violently disposed of their French masters.

Napoleon was unable to regain Santo Domingo and soon lost interest in establishing an empire in this hemisphere. At the same time Jefferson was concerned about access to New Orleans after Spain temporarily closed the port from American use. The President rationalized that only the purchase of New Orleans would secure American access to New Orleans and economic use of the Mississippi River.

Surprisingly, Napoleon was receptive to selling the entire region to recoup the financial losses suffered in the failed attempts to reclaim Santo Domingo. However, the Constitution did not allow for the expansion of the country through monetary negotiations. Nonetheless, Jefferson was able to ratify the sale by using the Federalist doctrine of implied interpretation. In a move of political genius, Jefferson was able to double the size of the United States while simultaneously reduce the Federalist influence in Washington DC.


The United States became a world imperial power after 1898, but the expansionist heritage was evident from the very beginning of the New Nation. Clearly, Jefferson wanted the country to reach from the Atlantic to the Pacific Oceans and the purchase of Louisiana contributed to that imperialistic vision. Unfortunately, imperialism usually implies the social and/or economic subjugation of native peoples. After Jefferson, successive presidents were forced to deal with the expansion of slavery and the forced assimilation of Native American Indians that would allow Americans to settle the West. The result was a succession of wars (War of 1812, The Mexican War, and the Civil War) that culminated with the Spanish-American War and the American ascension to world power status.


  1. DeConde, Alexander. This Affair of Louisiana. New York: Charles Schribner’s Sons, 1976.