In OTL, 1861 Delegates from several counties in western Virginia voted to secede from the (then) Confederate State of Virginia. This new state was then admited into The Union as a new state, West Virginia.
But WI West Virginia wasn't the only state to be created by seceding from The Confederacy? WI other counties in Border States decided to form their own governments? Would these new states join The Union, or become Independent Nations? How would this affect The US Civil War and American History?