Answer:
they limited westward exspansion and exploration
Explanation:
Mostly they affected it through their imperialism. They would colonize and take over countries for resources, and with them they would bring their technologies and things that they needed. After they left these things stayed, things like telephone and telegram lines and similar things. Culturally, they would mostly disregard the local culture and impose their own which would often be accepted and kept by the locals, but often there was also warfare.
Because the u.s dropped an atomic bomb into the middle of japan and threaten to do another one
John Adams was the president who sacrificed his popularity.
