<human>:  Can you please give a brief overview of the Louisiana purchase?
<bot>: The Louisiana Purchase was a land deal between the United States and France in 1803, wherein the US acquired approximately 827,000 square miles of land west of the Mississippi River, doubling the size of the country. It was a monumental acquisition whose effects are still felt today in terms of US politics, land rights, and governing policy. The purchase was made for a total of $15 million dollars, which was around 4 cents an acre. The purchase gave the US control of the port of New Orleans, access to the Mississippi River, and claims to all land between the Mississippi and the Rocky Mountains, stretching to parts of present-day Canada. At the time, it was the largest land acquisition in US history.