What territory did the United States buy from France in 1803?

Why this is the answer

The land the United States bought from France in 1803 was the Louisiana Territory, and USCIS accepts either that full name or simply "Louisiana." It ran west from the Mississippi River to the Rocky Mountains and covered about 828,000 square miles. France was paying for wars in Europe and needed money, so it sold the whole territory for 15 million dollars. The treaty was signed in Paris on April 30, 1803, and the purchase doubled the size of the country. No other land acquisition in American history is larger. The deal mattered for practical reasons too. Farmers shipped their products down the Mississippi, and the city of New Orleans was a major shipping port. Once the territory was American, they could send their goods downriver without asking permission from another country. Meriwether Lewis and William Clark then led an expedition to map the new land. Thomas Jefferson gets the credit for the purchase, and that gives you a free link between two questions. The official list of things Jefferson is famous for includes "doubled the size of the United States (Louisiana Purchase)," right next to "third president of the United States." Learn one and you already have an answer for the other. The purchase also had a heavy cost for Native Americans. As more people moved west into the new territory, conflicts and wars with them grew. Between the 1830s and the 1850s, the Cherokee, Muscogee, Seminole, Chickasaw and Choctaw nations were forced from their homelands in the South to land inside the Louisiana Territory. That journey is remembered as the Trail of Tears, because thousands died of disease and starvation along the way. A likely mix-up is naming a different piece of land the country gained in the 1800s. The Southwest is a later story: it came from Mexico after a war over Texas and other land, fought from 1846 to 1848. Tie the year to the seller, 1803 and France, and the right name follows.