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

What does this answer mean?

In 1803, the United States bought the Louisiana Territory from France. USCIS accepts "Louisiana Territory" or simply "Louisiana."

The deal is known as the Louisiana Purchase. The treaty was signed on April 30, 1803, while Thomas Jefferson was president. For $15 million, the United States got about 828,000 square miles of land west of the Mississippi River, which roughly doubled the size of the country.

The territory was far larger than today's state of Louisiana.

This is why "doubled the size of the United States (Louisiana Purchase)" is one of the accepted answers to the question about what Thomas Jefferson is famous for. If you learn the two questions together, each one helps you remember the other.

At the interview, say "the Louisiana Territory" or "Louisiana."