West Virginia became a state following the Wheeling Conventions, breaking away from Virginia during the American Civil War. The new state was admitted to the Union on June 20, 1863, and was a key Civil War border state. West Virginia was the only state to form by seceding from a Confederate state, and was one of only two states formed during the American Civil War (the other one being Nevada, which separated from Utah Territory).
West Virginians remained distrustful of and distrusted by Confederates for generations to come.
During both the Second Mexican War and the Great War, West Virginia was used as a staging area for US invasions of the Confederacy. The Second Mexican War invasion failed, the Great War invasion succeeded.
At the end of the Great War, the C.S. extracted territorial concessions from the Confederate state of Virginia, which extended West Virginia's borders to the Rappahannock River. The U.S. sought to prevent Washington, DC from being threatened or occupied ever again. The inhabitants of the annexed area were not content with this state of affairs, identifying themselves as Confederate citizens under military occupation.
Sensitive about the fate of Washington - still officially the US capital, even though Philadelphia was the de facto capital - U.S. President Al Smith refused to include the new West Virginia territory among the territories returned to the Confederacy under the Richmond Agreement in 1940, and remained steadfast in that refusal into the next year. C.S. PresidentJake Featherston used his refusal as a casus belli for launching the Second Great War.
During the Second Great War, West Virginia was the staging area for Daniel MacArthur's invasion of Virginia. The Freedom Party encouraged Confederate diehards within the annexed territories to sabotage US supply lines and support forces, to which the US authorities reacted with ruthless acts of retaliation.