Answer:
McCormick's reaper ensured that raising wheat would remain the main economic activity in the Midwest. New machines and new improvements in transportation helped farmers plant more acres of cash crops, crops planted strictly for sale. hope this helped
Preemption
This doctrine is centered around the attempt to repel or defeat a perceived imminent offensive or invasion. The aim is to gain a strategic advantage in an impending (allegedly unavoidable) conflict shortly before it materializes into a crisis. Its principles include unilateralism and the use of preventative war.
Both Europe and Japan had a "cast system" you could say, where peasants worked the land that the nobles owned. (The Japanese had their own terms for the people, I just can't remember them.) During this time, Europe had knights and these Knights had a code called Chivalry. Over in Japan, there were Samurai with a very similar code which was called Bushido. Hope this helps.