What were the border states during the civil War?
Delaware, Maryland, Kentucky and Missouri, and subsequently, West Virginia. West Virginia was admitted as a state to the Union in June of 1863.
During the American Civil War there were five states which stayed neutral and were given the name "border" states. They were called border states because they each bordered a free state and were aligned with the union. The five border states were Delaware, Kentucky, Maryland, Missouri, and West Virginia.