In the colorful jargon of the Civil War, the "Copperheads" were Northern Democrats who supported the war, but with some reservations. They opposed what they considered to be unconstitutional attacks on states' rights, including the outright abolition of slavery, and the suspension of the writ of habeas corpus by President Lincoln.

Historian Richard O. Curry, an authority on the creation of West Virginia, points out that the Copperhead movement had strong adherents in the state, including John S. Carlile, an early proponent of statehood who later reversed course. While historians once puzzled over Carlile's vote against the creation of West Virginia, Curry finds that it makes sense if his Copperhead philosophy, expressed in numerous speeches and articles, is examined. For example, as U.S. senator from loyalist Reorganized Virginia, Carlile criticized the Emancipation Proclamation. Curry points out that Carlile's opposition to the Willey Amendment, the U.S. Senate action that cleared the way for admission of West Virginia to the Union by providing for the abolition of slavery in the new state, was based not on opposition to the creation of the new state but on his view that Congress could not impose its will on the states, particularly dictating the terms of ending slavery.

Carlile was not alone in his views. Other conservative unionists of Western Virginia grew concerned as the Civil War developed into a crusade against slavery. Among them were John J. Davis, Andrew Wilson, John C. Vance, Sherrard Clemens, William W. Brumfield, and John S. Burdett. Daniel Lamb was among those who opposed statehood if it meant giving in to "abolitionist fanaticism." While the Copperhead movement largely failed to win any major concessions during the Civil War, Curry concludes that an alliance between ex-Confederates and Copperheads in the late 1860s helped speed the end of Reconstruction in West Virginia. This resulted in the creation of a new state constitution in 1872 and a shift of power from Republicans to Democrats.