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Louisiana Purchase: Primary Documents in American History

The Louisiana Purchase treaty was ratified by the Senate on October 20, 1803. This guide provides access to digital materials at the Library of Congress, links to related external websites, and a print bibliography.

Introduction

The Louisiana Purchase is considered the greatest real estate deal in history. The United States purchased the Louisiana Territory from France at a price of $15 million, or approximately four cents an acre. The Louisiana Purchase Treaty was signed in Paris on April 30, 1803. The ratification of the treaty by the Senate on October 20, 1803, doubled the size of the United States and opened up the continent to its westward expansion.