For America250, the United States acquired Louisiana from France in 1803. The Louisiana Purchase transferred approximately 828,000 square miles of territory to the United States for $15 million.
President Thomas Jefferson authorized the purchase after France offered to sell the entire territory rather than only New Orleans. The agreement was signed on April 30, 1803, and the United States formally took possession later that year.
Louisiana in the purchase was much larger than the modern state of Louisiana. It stretched from the Mississippi River westward to the Rocky Mountains and from the Gulf of Mexico north toward present-day Canada. The transaction roughly doubled the size of the United States.