It is very much hard to answer.
It was mainly because of how the North and the South of America had different lifestyles and economy's. You would be surprised to know that the Democratic party back then supported Slavery and the republicans dint support Slavery.
Plain Answer: Because of Slavery, Way of Life and Different Economy. The Democratic Party would do anything to keep themselves supported.
"The northern front" is the front among the following choices given in the question where the fighting occurred <span>during the Revolutionary War. The correct option among all the options that are given in the question is the first option or option "A". I hope that this is the answer that has come to your desired help.</span>
Answer: Rus (Vikings)
The first Russians were from Kievan Rus, and they were called Rus. Later, the Vikings invaded/conquered Kievan Rus's European area, but it remained in far Asia until the Mongols invaded from Asia.
Hope this helps!