Lesson 4: A Changing Nation

Key Idea

In the early 1800s, President Thomas Jefferson aimed to secure American trade on the Mississippi River by purchasing the port of New Orleans from France. Access to this port was critical for western farmers to ship their goods to market.

At the same time, France's leader, Napoleon Bonaparte, needed money to fund his wars in Europe. His ambitions for a North American empire had been thwarted by the successful Haitian Revolution, a massive slave revolt that established an independent nation. As a result, Napoleon offered to sell the entire Louisiana Territory. In 1803, the United States accepted the deal, known as the Louisiana Purchase, for $15 million, nearly doubling the country's size.

Key Idea

After the Louisiana Purchase, President Thomas Jefferson commissioned an expedition to explore the vast new territory. He appointed Meriwether Lewis and William Clark to lead the group. Their mission was to map the land, document its natural resources, establish trade with Native American nations, and search for a water route to the Pacific Ocean.

The expedition, officially called the Corps of Discovery, journeyed from St. Louis to the Pacific coast. With crucial help from their Shoshone guide, Sacagawea, the explorers gathered extensive information about the West's geography, plants, and animals. Though they did not find a direct water route, their journey established a U.S. claim to the Oregon region, paving the way for future westward expansion.

Key Idea

During Thomas Jefferson's presidency, the United States faced significant foreign policy challenges. In the Mediterranean Sea, pirates from the North African Barbary States demanded tribute, or protection money, from American merchant ships. When Jefferson refused to pay, he sent the U.S. Navy to protect American shipping, leading to the First Barbary War.

Meanwhile, a larger conflict between Britain and France created problems for the U.S. on the Atlantic Ocean. Both nations seized American ships to stop them from trading with the enemy. The British also engaged in impressment, the practice of kidnapping American sailors and forcing them to serve in the British navy. This violation of American neutrality angered many citizens.