What 1803 land deal nearly doubled the size of the United States?

The Louisiana Purchase was the 1803 land deal that nearly doubled the size of the United States.

The United States acquired the Louisiana Territory from France for $15 million. The treaty was signed in Paris on April 30, 1803, and the United States formally took possession later that year. The purchase covered about 828,000 square miles west of the Mississippi River, although the territory’s exact boundaries were disputed.

President Thomas Jefferson had initially authorized negotiations focused on New Orleans and navigation of the Mississippi River. French officials unexpectedly offered the entire territory, and American negotiators Robert R. Livingston and James Monroe accepted the opportunity.

The purchase opened a vast area to U.S. exploration and later settlement, including land that became part of 15 present-day states and two Canadian provinces. The Lewis and Clark Expedition began in 1804 to explore and map part of the newly acquired region.