Alexander The Great's generals divided into 3 kingdoms ruled by his former commander
First he wanted to take revenge on the countries that made the Versailles treaty because it was unfair to Germany. Then he wanted to cleanse the world of Jews, Slavs, and anyone who was not of the Aryan race.
United States was an agrarian-based nation. Prior to World War II, people were involved in agriculture than other existing industries. Technological improvements in farming introduced during the war years reduced farming dependencies on manual labor freeing people to move to the cities to find white collar jobs after the war.
I forgot what happened. A bunch of things happened.