What was formed from five western counties in the civil war?

During the Civil War, the five western counties of Virginia—Hampshire, Hardy, Pendleton, Grant, and Mineral—formed the new state of West Virginia. This decision was driven by the counties' opposition to Virginia's secession from the Union. West Virginia was officially admitted to the Union on June 20, 1863, becoming the 35th state. The creation of West Virginia was significant as it represented a split from a Confederate-aligned state to join the Union.