When the United States purchased me. I almost doubled the country's size. What am I?

The Louisiana Territory

Explanation:

When the Thomas Jefferson purchased the Louisiana territory in 1803, it nearly doubled the the country's size.

I think it's Louisiana that was bought and almost doubled the size. Because in 1803, the United States nearly doubled in size when it bought the Louisiana Territory in a deal that shaped history.

Hope this helps :)

answer; ///i do believe that the correct answer for the above is ( which states would be free and which states would have check first good