Bushwhacking was a form of guerrilla warfare during the American Civil War that was particularly prevalent in rural areas where there were sharp divisions between those favoring the Union and Confederacy in the conflict. The perpetrators of the attacks were called bushwhackers.
Bushwhackers were not generally part of the military command and control of either side. While bushwhackers conducted a few well-organized raids in which they burned cities, most of the attacks involved ambushes of opponent individuals or families in rural areas. In areas affected by bushwhacking the actions were particularly insidious since it amounted to a fight of neighbor against neighbor and the attacks bordered on vigilantism. Since the attacks were non-uniformed, the government response was complicated by trying to decide whether they were legitimate military attacks or criminal actions.
Pro-Union guerrilla fighters in Kansas were called "jayhawkers". They used tactics similar to the bushwhackers. A typical jayhawker action was a cross border raid into Missouri.
In some areas, particularly the Appalachian regions of Tennessee and North Carolina, the term bushwhackers was used for Union partisans who attacked Confederate forces. During the Gettysburg Campaign, Pennsylvanian civilians at times bushwhacked stragglers from the Army of Northern Virginia.
In Missouri, however, secessionist bushwhackers operated outside of the Confederate chain of command. On occasion, a prominent bushwhacker chieftain might receive formal Confederate rank (notably William Clarke Quantrill), or receive written orders from a Confederate general (as "Bloody Bill" Anderson did in October 1864 during a large-scale Confederate incursion into Missouri, or as when Joseph C. Porter was authorized by Gen. Sterling Price to recruit in northeast Missouri). Missouri guerrillas frequently assisted Confederate recruiters in Union held territory. For the most part, however, Missouri's bushwhacker squads were self-organized groups of young men, predominantly from the slave holding counties along the Missouri and Mississippi rivers, who took it upon themselves to attack Federal forces and their Unionist neighbors, both in Kansas and Missouri, the latter in response to what they considered a Federal invasion of their home state.
William Quantrill led a raid in August 1863 on Lawrence, Kansas, burning the town and murdering some 200 men and boys in the Lawrence Massacre. The raiders justified the raid in retaliation for the Sacking of Osceola,Missouri two years earlier (in which the town was set aflame and at least nine men killed) and for the deaths of five female relatives of bushwhackers killed in the collapse of a Kansas City, Missouri jail. Following the Lawrence raid, the Union district commander, Thomas Ewing, Jr., ordered the total depopulation of all men, women, and children (both Unionists and Southern sympathizers) of three and a half Missouri counties along the Kansas border from Kansas City, Missouri south, under his infamous General Order No. 11. (The Missouri-Kansas border conflict was in many ways a continuation of Bleeding Kansas violence.) In other areas, individual families (including that of Jesse and Frank James and the grandparents and mother of future President Harry Truman) were banished from Missouri.
Next to the attack on Lawrence, the most notorious atrocity by Confederate bushwhackers was the murder of 22 unarmed Union soldiers pulled from a train in the Centralia Massacre in retaliation for the earlier execution of a number of Anderson's own men. In an ambush of pursuing Union forces shortly thereafter, the bushwhackers killed well over 100 Federal troops. In October 1864, "Bloody Bill" Anderson was tricked into an ambush and killed by state militiamen under the command of Col. Samuel P. Cox. Anderson's body was displayed and his head was severed.
In 1867, near Nevada, Missouri, a band of bushwhackers shot and killed Sheriff Joseph Bailey, a former Union brigadier general, who was attempting to arrest them.