The signing of the Louisiana Purchase in 1803 brought over 800,000 square miles of new lands to the U.S. France sold the lands to the U.S. for $15 million.
In the years following the treaty signing, all or parts of 15 states from the Mississippi River to the Rocky Mountains and from the Canadian border to the Gulf of Mexico would be formed out of the acquired lands. With the signing, the United States could now claim to territory from the Atlantic to the Pacific coasts.
The Louisiana Purchase Exposition, or 1904 World's Fair, held in St. Louis commemorated the centennial of this great land acquisition. It sought to demonstrate the advances and progress to that day and what these meant to mankind both then and in the future.