Bushwhacking was a form of guerrilla warfare common during the American Revolutionary War, American Civil War and other conflicts in which there were large areas of contested land and few governmental resources to control these tracts. This was particularly prevalent in rural areas during the Civil War where there were sharp divisions between those favoring the Union and Confederacy in the conflict. The perpetrators of the attacks were called bushwhackers. The term "bushwhacking" is still in use today to describe ambushes done with the aim of attrition.
Bushwhackers were generally part of the irregular military forces on both sides. While bushwhackers conducted well-organized raids against the military, the most dire of the attacks involved ambushes of individuals or families in rural areas. In areas affected by bushwhacking, the actions were particularly inflammatory since they often amounted to fighting between neighbors, to settle personal accounts. Since the attacks were non-uniformed, the government response was complicated by trying to decide whether they were legitimate military attacks or criminal, terrorist actions.
The term "bushwhacker" came into wide use during the American Civil War (1861-1865): it became particularly associated with the Confederate guerrillas of Missouri, where such warfare was most intense. Guerrilla warfare also wracked Kentucky, Tennessee, northern Georgia, Arkansas, and northern Virginia, among other locations. Two bands operated in California in 1864.