The Louisiana Purchase of 1803 brought into the United States about 828,000 square miles of territory from France, thereby doubling the size of the young republic.

At $15 million, the Louisiana Purchase might sound like a relatively small real estate deal in today’s market. But it nearly doubled the size of the United States when it was signed on April 30, 1803.

Louisiana Purchase

What was the impact of the Louisiana Purchase? The Louisiana Purchase eventually doubled the size of the United States, greatly strengthened the country materially and strategically, provided a powerful impetus to westward expansion, and confirmed the doctrine of implied powers of the federal Constitution.

It became the country’s 18th state and the first one to be created from land acquired by the Louisiana Purchase. The US also gained control of the New Orleans port city and the Mississippi River, both important for supporting trade and industrialization of the region.

In 1762, during the French and Indian War, France ceded its America territory west of the Mississippi River to Spain and in 1763 transferred nearly all of its remaining North American holdings to Great Britain. In 1801, Spain signed a secret treaty with France to return Louisiana Territory to France.

Spain secretly acquired the territory from France near the end of the Seven Years’ War by the terms of the Treaty of Fontainebleau (1762). Louisiana was later and briefly retroceded back to France under the terms of the Third Treaty of San Ildefonso (1800) and the Treaty of Aranjuez (1801).

Jefferson was excited for the possibilities inherent in the Louisiana Purchase but also worried about its constitutionality. Jefferson believed in a…

The Louisiana Purchase was very controversial at the time. President Jefferson believed in a strict construction of the US Constitution — unless the Constitution specifically granted a power to the government, the power belonged to the people.