The Louisiana Purchase and Early Exploration

The Louisiana Purchase was an agreement on April 30, 1803, in which the United States bought a massive area of land from France for about 15 million dollars. The purchase nearly doubled the size of the country by adding territory from the Mississippi River to the Rocky Mountains.

Jefferson wanted to secure control of the Mississippi River and the port of New Orleans, which American farmers used to ship their goods. When France offered to sell the entire territory, Jefferson seized the opportunity to dramatically expand the young nation.

Meriwether Lewis and William Clark were explorers commissioned by Jefferson in 1804 to map the Louisiana Territory and find a route to the Pacific Ocean. Their expedition traveled over 8,000 miles, documented hundreds of new plant and animal species, and met dozens of American Indian nations.

As American settlers moved into the Louisiana Territory, they came into conflict with the many American Indian nations who had lived on that land for generations. These conflicts over land, resources, and sovereignty would intensify throughout the 19th century.

The expedition provided the first detailed maps and scientific descriptions of the vast western territory. The information Lewis and Clark gathered encouraged later settlers, helped the government understand what they had purchased, and opened the way for westward expansion.

Before 1803, the United States extended from the Atlantic coast to the Mississippi River. The Louisiana Purchase added approximately 828,000 square miles of territory, stretching from the Mississippi to the Rocky Mountains and nearly doubling the size of the country.