Why did the citizens of western virginia form their own government and ask to be admitted to the union as a separate state?

They thought slavery was terrible and they didn't want to take sides with Southern Virginia, where slavery was the main part of the economy and the society. They thought it was immoral, selfish, and cruel. They didn't want to be a part of the movement that supported slavery. (during the civil war)

I hope this helps!
~kaikers