Final answer:
The Louisiana Purchase doubled the size of the United States, gave it control over important trade routes and resources, and strengthened its international influence.
Step-by-step explanation:
The Louisiana Purchase had a significant impact on the US's international influence. It doubled the size of the United States and provided the country with access to important trade routes and resources. The acquisition of the port of New Orleans also gave the US control over a crucial trade hub. This expansion of territory and trade opportunities strengthened the US's position on the global stage and increased its influence internationally.