Who was a northerner who went to the south during reconstruction to work in business or politics

Many people actually did this. They were called carpetbaggers. They came to the south seeking to take advantage of the power vacuum left in the wake of the civil war.

Today, people that move to a new location purely for political gains are still often called carpetbaggers.

The second , larger puritan colony of massachusetts bay was conceived as a "city upon a hill". but it also struggled with internal turmoil like the salem witch trials and external conflicts like king philip's (metacom's) war.