There were a series of waves of Irish Immigrants who came to North America starting from the 18th century. These first immigrants would settle in the states of Maryland and Pennsylvania. However, during the beginning of 1800, working-class Irish people who came to the country started settling in the port city of Boston, Massachusetts. As the location was suitable because of the job opportunities matched with these immigrants qualifications.
The United States chose to use a federal republic model (E) when they were writing the Constitution to frame the construction of the U.S Government.
As a federal republic power is shared between the central government and federal entities which in the case of the U.S. are states. This created a federal system whereby powers were divided between states and the national government and also a republic whereby citizens would elect representatives to represent their interests.
Not 100% sure but I think it made the North see that the war wasn't going to be done by Christmas as many had thought.
