Answer:
a. Columbian Exchange
Explanation:
The first Europeans that managed to get tot he New World discovered lot of things that can be used back in their homelands. Lot of new crops were discovered, animals, vast fertile lands, as well as gold and silver. Once these things were introduced back in Europe the word quickly spread out, so the interest for exploration skyrocketed. Lot of people wanted to get out of Europe and go into the New World in order to get to this things, start a new life, and get rich. This resulted in countless explorations and mass migrations toward the New World.
The hope that Johnson have in accomplishing in which he
enacts a harsher plan was because he hopes to avoid secession that may happen
in the future in which, there might be a presence of withdrawal of membership
of which he does not want to happen.
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.
