In West Virginia, some took advantage of the Civil War to settle personal grievances or pursue personal gain or other nonmilitary ends. They were called bushwhackers from their habit of ambushing or "bushwhacking" their adversaries from under cover. Usually they claimed to be attached to one side in the struggle, often the South. Early in the war, the Confederate Congress authorized the formation of partisan ranger companies, and the state of West Virginia formed Unionist militia companies. These groups, while technically authorized by the appropriate civil government, frequently operated independently of any formal military command. The Partisan Ranger Law passed by the Confederate Congress was later repealed when regular officers including Robert E. Lee complained that they siphoned off men and that they failed to carry out strategic military plans in favor of seeking loot and glory. On one occasion, Lee described the partisans as "a band of thieves, stealing, pillaging, plundering and doing every manner of mischief and crime."

For example, the Moccasin Rangers terrorized residents in Calhoun County. Boyd Stutler, West Virginia's Civil War historian, wrote that the Rangers "had a certain nuisance value . . . but generally were not a credit to the Confederate cause. It was a great time to pay off old scores, and many of the acts of the Rangers were more personal than political." In Jackson and Roane counties, opposing bands of Northern and Southern sympathizers committed atrocities that resulted in a feud that continued into the 1880s. These so-called Roane County or Jackson County Land Wars, also known as the Bruen Land Wars, were carried over from murders and attacks perpetrated during the war.

The worst partisan actions seemed to have been in areas where sympathies were divided rather than in those where either the Northern or Southern views predominated. At least one group in southern West Virginia appears to have escaped being cast in the same mold as their disrespectable comrades elsewhere. Capt. W. D. Thurmond organized a company of partisan rangers in Monroe County. The company served throughout the war, occasionally attaching itself to larger Confederate units for service in the New River Gorge and in the Greenbrier Valley. On the other hand, Anderson Hatfield's "Wildcats" in Logan County engaged in acts that some historians attribute to fostering hatreds leading to the Hatfield-McCoy feud.