What territory did the US buy from France in 1803?

The United States purchased the Louisiana Territory from France in 1803, which significantly expanded the size of the nation. This acquisition, known as the Louisiana Purchase, involved buying approximately 828,000 square miles of territory, which doubled the size of the U.S. at that time.

The purchase was pivotal because it not only provided access to vast natural resources and land for settlement but also secured control over the port of New Orleans, essential for trade and navigation along the Mississippi River. The deal was negotiated by President Thomas Jefferson, who was keen on westward expansion and the agrarian society he envisioned for the country.

The other options pertain to different territories acquired at different times: Florida was acquired from Spain in 1819, Alaska was purchased from Russia in 1867, and the Oregon Territory was claimed through various treaties and colonization, particularly with the British in the mid-19th century. Thus, the Louisiana Territory remains the correct answer to this particular question about the 1803 purchase.