Louisiana Purchase, western half of the Mississippi River basin purchased in 1803 from France by the United States; at less than three cents per acre for 828,000 square miles (2,144,520 square km), it was the greatest land bargain in U.S. history. The purchase doubled the size of the United States, greatly strengthened the country materially and strategically, provided a powerful impetus to westward expansion, and confirmed the doctrine of implied powers of the federal Constitution.
The Louisiana Territory under Spanish and French rule
The Louisiana Territory had been the object of Old World interest for many years before 1803. Explorations and ... (100 of 1,233 words)