Answer:
The Americans identified as "Americans", and the population also contained people who were not from Britain originally (neither is their family line). However, it is a civil war, as the governmental system was created by British subjects, and they were a royal colony. The British government technically ruled over the American colonies, but only started to use their power after the American Indian War to raise funds to pay for their debts. It is just a matter of identities and the historical truth.
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