Why did West Virginia separate from Virginia?

During the Civil War, Virginians that lived to the west of the Allegheny Mountains were not happy with the government of Virginia. So when the Richmond government seceded, they declared themselves the legitimate government of Virginia, and authorized the division of the two states.
West Virginians formed their own government to fight for the North.

Western Virginia was not happy with a multitude of things that the central Virginia government on the east side of the mountains had done. They disliked the taxes and rules being imposed upon them. Numerous politicians took advantage of the secession of Virginia from the Union to create an alternative government that ratified and approved the split, creating the new state.

West Virginia's early history from 1609 until 1863 is largely shared with Virginia, of which it was a part until Virginia seceded from the Union in 1861. The delegates of the 40 western counties who opposed secession formed their own government, which was granted statehood in 1863.

The growing differences between Eastern and Western Virginia in the mid 1800's contributed to WV's desire to become a separate state. Issues included: National Political Leaders, Attitudes toward Voting, Geographical influences, and attitudes towards slavery.