The United States bought the Louisiana Territory from France in 1803. This vast territory encompassed approximately 828,000 square miles (about 530 million acres) west of the Mississippi River, nearly doubling the size of the United States at the time. The purchase included land that would later become all or parts of 15 present-day U.S. states, such as Louisiana, Arkansas, Missouri, Iowa, Oklahoma, Kansas, Nebraska, and portions of Minnesota, North Dakota, South Dakota, Montana, Wyoming, Colorado, New Mexico, and Texas. The deal was made for $15 million, which amounted to roughly 4 cents per acre—a remarkable bargain. The Louisiana Purchase extended U.S. sovereignty from the Mississippi River to the Rocky Mountains and from the Gulf of Mexico northward, significantly enhancing the country's material and strategic strength and fueling westward expansion