America 250: The Louisiana Purchase

The landmark agreement roughly doubled the size of the young American nation and opened the door to westward expansion and exploration.

The Louisiana Purchase in 1803 was a landmark agreement in which the United States acquired vast territory from France for $15 million. The deal added about 828,000 square miles and roughly doubled the size of the young nation. The land stretched from the Mississippi River to the Rocky Mountains and from the Gulf of Mexico to present-day Canada. It later became all or part of 15 U.S. states. The purchase opened the door to westward expansion and exploration. It also strengthened the authority of the federal government by establishing the principle of implied powers.