The Louisiana Territory was the land added to the United States as a result of the 1803 Louisiana Purchase. It contained 828,800 square miles (2,147,000 square kilometers) of land, including most of the Mississippi River valley and the port city of New Orleans. The territory was purchased for around $15 million and doubled the size of the United States. While such a significant acquisition of land was an advantageous move for the United States, the purchase produced some problems and complications.
Tensions with Spain
While the Louisiana Territory originally was settled by France, it had been controlled by Spain since France's defeat in the Seven Years' War in 1763. While France regained control over the territory in 1800, part of the treaty with Spain was a promise that France would not sell the Louisiana Territory to a third party. By purchasing the territory from France, the United States was directly antagonizing Spain. Opponents of the Louisiana Purchase feared that Spain would attempt to reclaim the Louisiana Territory by force.
The Slave Debate
The acquisition of the Louisiana Territory rekindled the smoldering debate over slavery in the United States. Prior to the Louisiana Purchase, a geographical and political balance existed between slave and free states, with neither side possessing the population or political power to force an agenda upon rival states. The expansive Louisiana Territory threatened to upset that balance. In the ensuing debates, the issue became more politically volatile and the sides grew more polarized, contributing to the deepening divide that eventually would become the Civil War.
President Thomas Jefferson himself had grave doubts regarding the constitutionality of the Louisiana Purchase. A strict constitutionalist, he had based his entire political career on exercising only those powers explicitly granted by the Constitution. The expansion of the territory of the United States was not a power covered by the Constitution. Proponents of the purchase argued that it fell under the Tenth Amendment, which granted all other rights and powers not covered to the states and people. Despite this argument, Jefferson's decision to go ahead with the purchase opened him up to accusations of political hypocrisy and decreased the power and prestige of his party.
Existing Land Claims
While the Louisiana Purchase added the territory as a whole to the United States, land disputes on a smaller scale erupted immediately. With the Spanish government no longer in control, the oral contracts and traditional family holdings of existing landowners led to complicated legal disputes. The laws surrounding squatter's rights were much harsher in the United States than in the Spanish territories, leading to widespread outcry within the territory. In addition, much of the land included in the Louisiana Purchase was owned by Native American tribes and nations. It would take another century of war, treaties and negotiation before significant portions of the Louisiana Territory fell under the ownership of the United States in fact.