Final answer:
The statement that the Louisiana Purchase doubled the territory of the United States is true; it was a significant land acquisition in 1803 that extended the nation's boundaries substantially.
Step-by-step explanation:
The statement in the question, "The Louisiana Purchase doubled the territory of the United States," is true. The acquisition took place in 1803 when the United States, under President Thomas Jefferson, bought approximately 828,000 square miles of land from France. This massive land deal roughly doubled the size of the United States at that time, extending the nation's boundaries to the west and including land that would eventually become 15 new states.