Final answer:
The desire to form a separate government in western North Carolina in the late 1700s was driven by opposition to British colonial rule, specifically the Royal Proclamation of 1763 that limited colonization and economic prospects west of the Appalachian Mountains, leading to the American Revolution.
Step-by-step explanation:
The principal reason to form a separate government in western North Carolina in the late 1700s was b) Opposition to British colonial rule. This sentiment stemmed from the Royal Proclamation of 1763, which set the Appalachian Mountains as the western boundary for settlement. The colonists regarded this proclamation as tyrannical since it restricted their movement and economic opportunities, especially for those who had already received land grants west of the Appalachians.
Moreover, the proclamation also aimed to prevent conflict with French and Native American inhabitants of the region. The British government's subsequent enforcement of mercantilist policies, imposition of new taxes, restriction of economic opportunities, and interference with colonial self-government increasingly alienated the colonists, planting the seeds for the American Revolution and the desire for an independent governance structure.