2. Gained control of the port of New Orleans
When the two U.S. statesmen, James Monroe, and Livingston, were sent to Paris to negotiate with France, the U.S.'s initial intention was to negotiate the acquisition of New Orleans and all or part of Florida, or just New Orleans, and if France didn't accept it either then, at least, they would have to secure U.S. access to the Mississippi and the port.
After negotiations took place, not only did the U.S. acquire new Orleans, but it also ended up acquiring the whole territory of Louisiana of approximately 828,000,000 square, almost half of what the U.S. is today.