How much land did the United States acquire in the Louisiana Purchase, a major expansion before America250?

The United States acquired approximately 828,000 square miles in the Louisiana Purchase, a major expansion before America250.

In 1803, the United States agreed to pay France 15 million dollars for the territory. The purchase covered much of the Mississippi River basin west of the river and substantially expanded the young republic's claimed land area.

The transaction resulted from changing European power politics. Napoleon Bonaparte had regained Louisiana from Spain, but difficulties in Saint-Domingue and the prospect of renewed war with Britain encouraged France to sell the territory.

The purchase did not mean that the land was empty or that every boundary was immediately settled. Indigenous nations already lived throughout the region, and American control expanded through later treaties, conflict, exploration, and settlement. The Lewis and Clark expedition began in 1804 to survey part of the new territory.