Answer: imperialism was a huge factor as well as urbanization. the first world war was a big part too.
Explanation:
Although there definitely existed "robber barons" who took advantage of a delicate and changing situation, most of these men were mostly well-meaning people who wanted to capitalize on an opportunity, and whose actions increased the welfare of many Americans.
Taxation without representation means that the colonists believed that they should not be taxed by a government, if they were not even allowed to hold office in said government. The colonists considered this a problem because even though the French-Indian war had put a dent in British economy, the colonists were not even allowed to decide whether the war should happen in the first place. After all it was their homeland. In addition the colonists, not being allowed to hold office, could not propose any modifications to the taxes.
Massachusetts is not one of the Middle Colonies. Massachusetts is one of the New England Colonies. I was founded in 1630. I hope that this helped. Have a good day!