Topic 4.3: The Louisiana Purchase and the Expansion of Slavery

What major event defined Jefferson’s presidency?

The Louisiana Purchase of 1803, which doubled the size of the United States and fundamentally changed its geography, economy, and politics.

From whom did the United States purchase the Louisiana Territory?

France, under the leadership of Napoleon Bonaparte.

What motivated Napoleon to sell the Louisiana Territory?

After losing interest in his North American empire—especially following the Haitian Revolution and his need for funds for European wars—Napoleon sold the land to focus on his ambitions in Europe.

How much did the Louisiana Purchase cost the United States?

$15 million, approximately three cents per acre, making it one of the greatest land deals in history.

What was Jefferson’s initial constitutional concern about the Louisiana Purchase?

As a strict constructionist, he believed the Constitution did not explicitly authorize the president to acquire new land or make such a purchase.

How did Jefferson justify the Louisiana Purchase despite his constitutional concerns?

He argued that the purchase was implied under the president’s power to make treaties, prioritizing national benefit over strict interpretation.

What precedent did the Louisiana Purchase set?

It expanded the implied powers of the federal government and showed that presidents could act pragmatically when national interests were at stake.

What immediate effect did the Louisiana Purchase have on the size of the U.S.?

It doubled the country’s size, adding 828,000 square miles of territory west of the Mississippi River.

How did the Louisiana Purchase affect relations with Indigenous peoples?

It intensified conflict and displacement as settlers, supported by the government, expanded into Native lands.

What major expedition explored the newly acquired Louisiana Territory?

The Lewis and Clark Expedition (1804–1806).

Who led the Lewis and Clark Expedition?

Meriwether Lewis and William Clark, commissioned by President Jefferson.

What were the goals of the Lewis and Clark Expedition?

To map the territory, establish relations with Indigenous nations, and identify natural resources and potential trade routes to the Pacific.

Who helped guide and interpret for Lewis and Clark?

Sacagawea, a Shoshone woman who played a crucial role as interpreter and symbol of peaceful intent.

What were the broader consequences of the Lewis and Clark Expedition?

It strengthened U.S. claims to the Pacific Northwest, provided valuable geographic and scientific data, and encouraged westward expansion.

How did the Louisiana Purchase impact domestic politics?

It bolstered Jefferson’s popularity but also revealed tensions within the Democratic-Republican Party between strict and loose constructionists.

What were the economic benefits of the Louisiana Purchase?

It opened vast areas of fertile farmland, expanded trade routes along the Mississippi River, and provided access to New Orleans, a key port city.

Why was New Orleans so important to the United States?

It was a vital commercial port for western farmers who relied on the Mississippi River to ship goods.

How did the acquisition of Louisiana affect slavery?

It reignited debates over the expansion of slavery into new western territories.

Why did the Louisiana Purchase complicate the slavery question?

The vast new lands required decisions about whether slavery would be permitted, creating sectional tensions between North and South.

What was the Missouri Territory’s significance in the slavery debate?

When Missouri applied for statehood in 1819 as a slave state, it triggered the first major political conflict over the balance between free and slave states.

What compromise resolved the Missouri statehood crisis?

The Missouri Compromise of 1820.

Who proposed the Missouri Compromise?

Henry Clay.

What were the terms of the Missouri Compromise?

Missouri entered as a slave state, Maine entered as a free state, and slavery was prohibited north of latitude 36°30' in the remaining Louisiana Territory.

Why was maintaining the balance between free and slave states so important?

It preserved equal representation in the Senate, preventing one region from dominating national policy.

What did the Missouri Compromise reveal about the U.S.?

It showed that sectional divisions over slavery were deep and growing, even during the so-called “Era of Good Feelings.”

How did the Louisiana Purchase indirectly lead to the Missouri Compromise?

By adding vast new lands that required governance and decision-making on slavery, the purchase set the stage for sectional conflict.

What long-term tension did the Missouri Compromise fail to resolve?

Whether slavery would expand with westward settlement or be restricted to the South, an issue that would later lead to the Civil War.

How did the Louisiana Purchase influence American identity?

It transformed the U.S. into a continental nation with a vision of westward expansion rooted in opportunity and empire-building.

How did Jefferson’s decision affect the presidency?

It expanded executive authority by showing that the president could take bold action for national benefit even when constitutional guidance was limited.

What overall legacy did the Louisiana Purchase leave on the United States?

It secured American control of the Mississippi River, doubled the nation’s size, accelerated westward migration, fueled debates over slavery, and set the pattern for future territorial expansion.